Variable effects of climate on forest growth in relation to climate extremes, disturbance, and forest dynamics

USGS Publications Warehouse

Itter, Malcolm S.; Finley, Andrew O.; D'Amato, Anthony W.; Foster, Jane R.; Bradford, John B.

2017-01-01

Changes in the frequency, duration, and severity of climate extremes are forecast to occur under global climate change. The impacts of climate extremes on forest productivity and health remain difficult to predict due to potential interactions with disturbance events and forest dynamics—changes in forest stand composition, density, size and age structure over time. Such interactions may lead to non-linear forest growth responses to climate involving thresholds and lag effects. Understanding how forest dynamics influence growth responses to climate is particularly important given stand structure and composition can be modified through management to increase forest resistance and resilience to climate change. To inform such adaptive management, we develop a hierarchical Bayesian state space model in which climate effects on tree growth are allowed to vary over time and in relation to past climate extremes, disturbance events, and forest dynamics. The model is an important step toward integrating disturbance and forest dynamics into predictions of forest growth responses to climate extremes. We apply the model to a dendrochronology data set from forest stands of varying composition, structure, and development stage in northeastern Minnesota that have experienced extreme climate years and forest tent caterpillar defoliation events. Mean forest growth was most sensitive to water balance variables representing climatic water deficit. Forest growth responses to water deficit were partitioned into responses driven by climatic threshold exceedances and interactions with insect defoliation. Forest growth was both resistant and resilient to climate extremes with the majority of forest growth responses occurring after multiple climatic threshold exceedances across seasons and years. Interactions between climate and disturbance were observed in a subset of years with insect defoliation increasing forest growth sensitivity to water availability. Forest growth was particularly

Ecological characteristics of old-growth Douglas-fir forests.

Treesearch

Jerry F. Franklin; Kermit Jr. Cromack; William Denison; Arthur McKee; Chris Maser; James Sedell; Fred Swanson; Glen Juday

1981-01-01

Old-growth coniferous forests differ significantly from young-growth forests in species composition, function (rate and paths of energy flow and nutrient and water cycling), and structure. Most differences can be related to four key structural components of old growth: large live trees, large snags, large logs on land, and large logs in streams. Foresters wishing to...

Structure and development of old-growth, unmanaged second-growth, and extended rotation Pinus resinosa forests in Minnesota, USA

USGS Publications Warehouse

Silver, Emily J.; D'Amato, Anthony W.; Fraver, Shawn; Palik, Brian J.; Bradford, John B.

2013-01-01

The structure and developmental dynamics of old-growth forests often serve as important baselines for restoration prescriptions aimed at promoting more complex structural conditions in managed forest landscapes. Nonetheless, long-term information on natural patterns of development is rare for many commercially important and ecologically widespread forest types. Moreover, the effectiveness of approaches recommended for restoring old-growth structural conditions to managed forests, such as the application of extended rotation forestry, has been little studied. This study uses several long-term datasets from old growth, extended rotation, and unmanaged second growth Pinus resinosa (red pine) forests in northern Minnesota, USA, to quantify the range of variation in structural conditions for this forest type and to evaluate the effectiveness of extended rotation forestry at promoting the development of late-successional structural conditions. Long-term tree population data from permanent plots for one of the old-growth stands and the extended rotation stands (87 and 61 years, respectively) also allowed for an examination of the long-term structural dynamics of these systems. Old-growth forests were more structurally complex than unmanaged second-growth and extended rotation red pine stands, due in large part to the significantly higher volumes of coarse woody debris (70.7 vs. 11.5 and 4.7 m3/ha, respectively) and higher snag basal area (6.9 vs. 2.9 and 0.5 m2/ha, respectively). In addition, old-growth forests, although red pine-dominated, contained a greater abundance of other species, including Pinus strobus, Abies balsamea, and Picea glauca relative to the other stand types examined. These differences between stand types largely reflect historic gap-scale disturbances within the old-growth systems and their corresponding structural and compositional legacies. Nonetheless, extended rotation thinning treatments, by accelerating advancement to larger tree diameter

Carbon Uptake and Storage in Old-Growth and Second-Growth Forests in Central Vermont

NASA Astrophysics Data System (ADS)

Lloyd, A. H.; Weisser, O.

2013-12-01

Managing forests towards the goal of maximizing carbon uptake and storage provides an important tool for climate change mitigation. There is significant spatial and temporal variation among forests, even within an ecosystem type, in annual uptake and storage of carbon. Understanding the causes for that variation is important in refining management practices and restoration goals that promote carbon storage. We explore the variation in carbon storage and uptake among forests differing in age in central Vermont, comparing young, intermediate-aged, and old-growth forests. We generally expected that younger forests would have a higher annual uptake of carbon than older forests. Significant uncertainty exists, however, about the temporal trajectory from a young, rapidly growing forest to an old-growth forest that may be in a steady-state, with no net uptake of carbon. Within each forest, we compare differences among functional groups of species (e.g., hardwoods versus softwoods) in contribution to overall forest carbon uptake and storage. Our study sites include an old-growth hemlock/mixed hardwood forest that has not been directly affected by human activities, and which contains trees upwards of 350 years old; a 130-year-old mixed hardwood forest that has recolonized former pasture land; and a 90-year-old mixed hardwood forest on formerly agricultural floodplain land. Carbon storage in live and dead biomass pools was estimated from allometric equations, based on repeated measurements of tree diameters in permanently marked study plots. Historical patterns of carbon storage in living biomass were estimated by reconstructing tree diameter from measured increment cores, and then estimating the living biomass in each year. As expected, the old-growth forest stored almost twice the C in live biomass as the two second-growth forests, which stored equivalent amounts of carbon, despite the difference in age. Dead biomass was a larger pool of C in the old-growth forest than in

Forest growth of Mississippi's north unit - A case study of the Southern Forest surveys growth estimation procedures

Treesearch

Dennis M. May

1988-01-01

This report presents the procedures by which the Southern Forest Inventory and Analysis unit estimates forest growth from permanent horizontal point samples. Inventory data from the 1977-87 survey of Mississippi's north unit were used to demonstrate how trees on the horizontal point samples are classified into one of eight components of growth and, in turn, how...

Comparison of an empirical forest growth and yield simulator and a forest gap simulator using actual 30-year growth from two even-aged forests in Kentucky

Treesearch

Daniel A. Yaussy

2000-01-01

Two individual-tree growth simulators are used to predict the growth and mortality on a 30-year-old forest site and an 80-year-old forest site in eastern Kentucky. The empirical growth and yield model (NE-TWIGS) was developed to simulate short-term (

Tree growth and competition in an old-growth Picea abies forest of boreal Sweden: influence of tree spatial patterning

USGS Publications Warehouse

Fraver, Shawn; D'Amato, Anthony W.; Bradford, John B.; Jonsson, Bengt Gunnar; Jönsson, Mari; Esseen, Per-Anders

2013-01-01

Question: What factors best characterize tree competitive environments in this structurally diverse old-growth forest, and do these factors vary spatially within and among stands? Location: Old-growth Picea abies forest of boreal Sweden. Methods: Using long-term, mapped permanent plot data augmented with dendrochronological analyses, we evaluated the effect of neighbourhood competition on focal tree growth by means of standard competition indices, each modified to include various metrics of trees size, neighbour mortality weighting (for neighbours that died during the inventory period), and within-neighbourhood tree clustering. Candidate models were evaluated using mixed-model linear regression analyses, with mean basal area increment as the response variable. We then analysed stand-level spatial patterns of competition indices and growth rates (via kriging) to determine if the relationship between these patterns could further elucidate factors influencing tree growth. Results: Inter-tree competition clearly affected growth rates, with crown volume being the size metric most strongly influencing the neighbourhood competitive environment. Including neighbour tree mortality weightings in models only slightly improved descriptions of competitive interactions. Although the within-neighbourhood clustering index did not improve model predictions, competition intensity was influenced by the underlying stand-level tree spatial arrangement: stand-level clustering locally intensified competition and reduced tree growth, whereas in the absence of such clustering, inter-tree competition played a lesser role in constraining tree growth. Conclusions: Our findings demonstrate that competition continues to influence forest processes and structures in an old-growth system that has not experienced major disturbances for at least two centuries. The finding that the underlying tree spatial pattern influenced the competitive environment suggests caution in interpreting traditional tree

Old-growth definition for wet pine forests, woodlands, and savannas. Forest Service general technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harms, W.R.

1996-09-01

All Forest Service Stations and Regions began developing old-growth definitions for specific forest types. Definitions will first be developed for broad forest types and based mainly on published information and so must be viewed accordingly. Refinements will be made by the Forest Service as new information becomes available. This document represents 1 of 35 forest types for which old-growth definition will be drafted.

Testing the accuracy of growth and yield models for southern hardwood forests

Treesearch

H. Michael Rauscher; Michael J. Young; Charles D. Webb; Daniel J. Robison

2000-01-01

The accuracy of ten growth and yield models for Southern Appalachian upland hardwood forests and southern bottomland forests was evaluated. In technical applications, accuracy is the composite of both bias (average error) and precision. Results indicate that GHAT, NATPIS, and a locally calibrated version of NETWIGS may be regarded as being operationally valid...

Observed forest sensitivity to climate implies large changes in 21st century North American forest growth.

PubMed

Charney, Noah D; Babst, Flurin; Poulter, Benjamin; Record, Sydne; Trouet, Valerie M; Frank, David; Enquist, Brian J; Evans, Margaret E K

2016-09-01

Predicting long-term trends in forest growth requires accurate characterisation of how the relationship between forest productivity and climatic stress varies across climatic regimes. Using a network of over two million tree-ring observations spanning North America and a space-for-time substitution methodology, we forecast climate impacts on future forest growth. We explored differing scenarios of increased water-use efficiency (WUE) due to CO2 -fertilisation, which we simulated as increased effective precipitation. In our forecasts: (1) climate change negatively impacted forest growth rates in the interior west and positively impacted forest growth along the western, southeastern and northeastern coasts; (2) shifting climate sensitivities offset positive effects of warming on high-latitude forests, leaving no evidence for continued 'boreal greening'; and (3) it took a 72% WUE enhancement to compensate for continentally averaged growth declines under RCP 8.5. Our results highlight the importance of locally adapted forest management strategies to handle regional differences in growth responses to climate change. © 2016 John Wiley & Sons Ltd/CNRS.

Measurement of Tree Growth in Tropical Forests

Treesearch

C. B. Briscoe

1961-01-01

The title of my paper--Measurement of Tree Growth in Tropical Forests--is somwhat misleading. Because tree and forest growth determination are essentially the same anywhere, most of what I have to say is as applicable in British Columbia, Japan, or New Zealand as it is in Ecuador or the Philipines.

Application of a Hybrid Forest Growth Model to Evaluate Climate Change Impacts on Productivity, Nutrient Cycling and Mortality in a Montane Forest Ecosystem.

PubMed

Seely, Brad; Welham, Clive; Scoullar, Kim

2015-01-01

Climate change introduces considerable uncertainty in forest management planning and outcomes, potentially undermining efforts at achieving sustainable practices. Here, we describe the development and application of the FORECAST Climate model. Constructed using a hybrid simulation approach, the model includes an explicit representation of the effect of temperature and moisture availability on tree growth and survival, litter decomposition, and nutrient cycling. The model also includes a representation of the impact of increasing atmospheric CO2 on water use efficiency, but no direct CO2 fertilization effect. FORECAST Climate was evaluated for its ability to reproduce the effects of historical climate on Douglas-fir and lodgepole pine growth in a montane forest in southern British Columbia, Canada, as measured using tree ring analysis. The model was subsequently used to project the long-term impacts of alternative future climate change scenarios on forest productivity in young and established stands. There was a close association between predicted sapwood production and measured tree ring chronologies, providing confidence that model is able to predict the relative impact of annual climate variability on tree productivity. Simulations of future climate change suggest a modest increase in productivity in young stands of both species related to an increase in growing season length. In contrast, results showed a negative impact on stemwood biomass production (particularly in the case of lodgepole pine) for established stands due to increased moisture stress mortality.

Direct observation of morphological evolution of a catalyst during carbon nanotube forest growth: new insights into growth and growth termination

NASA Astrophysics Data System (ADS)

Jeong, Seojeong; Lee, Jaegeun; Kim, Hwan-Chul; Hwang, Jun Yeon; Ku, Bon-Cheol; Zakharov, Dmitri N.; Maruyama, Benji; Stach, Eric A.; Kim, Seung Min

2016-01-01

In this study, we develop a new methodology for transmission electron microscopy (TEM) analysis that enables us to directly investigate the interface between carbon nanotube (CNT) arrays and the catalyst and support layers for CNT forest growth without any damage induced by a post-growth TEM sample preparation. Using this methodology, we perform in situ and ex situ TEM investigations on the evolution of the morphology of the catalyst particles and observe the catalyst particles to climb up through CNT arrays during CNT forest growth. We speculate that the lifted catalysts significantly affect the growth and growth termination of CNT forests along with Ostwald ripening and sub-surface diffusion. Thus, we propose a modified growth termination model which better explains various phenomena related to the growth and growth termination of CNT forests.In this study, we develop a new methodology for transmission electron microscopy (TEM) analysis that enables us to directly investigate the interface between carbon nanotube (CNT) arrays and the catalyst and support layers for CNT forest growth without any damage induced by a post-growth TEM sample preparation. Using this methodology, we perform in situ and ex situ TEM investigations on the evolution of the morphology of the catalyst particles and observe the catalyst particles to climb up through CNT arrays during CNT forest growth. We speculate that the lifted catalysts significantly affect the growth and growth termination of CNT forests along with Ostwald ripening and sub-surface diffusion. Thus, we propose a modified growth termination model which better explains various phenomena related to the growth and growth termination of CNT forests. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05547d

Growth of coast redwood and Douglas-fir following thinning in second-growth forests at Redwood National Park and Headwaters Forest Reserve

Treesearch

Phillip J. van Mantgem; Jason R. Teraoka; David H. LaFever; Laura B. Lalemand

2017-01-01

Managers of second-growth forests at Redwood National Park and the Bureau of Land Management’s Headwaters Forest Reserve encourage the development of late seral forest characteristics using mechanical thinning, where competing vegetation is removed to promote growth of residual trees. Yet the ability to quantify and reliably predict outcomes of treatments such...

Conserving old-growth forest diversity in disturbance-prone landscapes.

Treesearch

Thomas A. Spies; Miles A. Hemstrom; Andrew Youngblood; Susan Hummel

2006-01-01

A decade after its creation, the Northwest Forest Plan is contributing to the conservation of old growth forests on federal land. However, the success and outlook for the plan are questionable in the dry provinces, where losses of old growth to wildfire have been relatively high and risks of further loss remain. We summarize the state of knowledge of old-growth forests...

[Effects of forest gap size on the growth and form quality of Taxus wallichina var. mairei in Cunninghamia lanceolata forests].

PubMed

Ou, Jian de; Wu, Zhi Zhuang; Luo, Ning

2016-10-01

In order to clarify the effects of forest gap size on the growth and stem form quality of Taxus wallichina var. mairei and effectiveness of the precious timbers cultivation, 25 sample plots in Cunninghamia lanceolata forest gaps were established in Mingxi County, Fujian Province, China to determine the indices of the growth, stem form and branching indices of T. wallichina var. mairei seedlings. The relationships between the gap size and growth, stem form and branching were investigated. The 25 sample plots were located at five microhabitats which were classified based on gap size as follows: Class1, 2, 3, 4 and 5, which had a gap size of 25-50 m 2 , 50-75 m 2 , 75-100 m 2 , 100-125 m 2 and 125-150 m 2 , respectively. The evaluation index system of precious timbers was built by using hierarchical analysis. The 5 classes of forest gaps were evaluated comprehensively by using the multiobjective decision making method. The results showed that gap size significantly affected 11 indices, i.e., height, DBH, crown width, forking rate, stem straightness, stem fullness, taperingness, diameter height ratio, height under living branch, interval between branches, and max-branch base diameter. Class1and 2 both significantly promoted the growth of height, DBH and crown width, and both significantly inhibited forking rate and taperingness, and improved stem straightness. Class2 significantly improved stem fullness and diameter height ratio. Class1and 2 significantly improved height under living branch and reduced max-branch base diameter. Class 1 significantly increased interval between branches. Class1and2 significantly improved the comprehensive evaluation score of precious timbers. This study suggested that controlled cutting intensity could be used to create forest gaps of 25-75 m 2 , which improved the precious timber cultivating process of T. wallichina var. mairei in C. lanceolata forests.

Assessing biomass accumulation in second growth forests of Puerto Rico using airborne lidar

NASA Astrophysics Data System (ADS)

Martinuzzi, S.; Cook, B.; Corp, L. A.; Morton, D. C.; Helmer, E.; Keller, M.

2017-12-01

Degraded and second growth tropical forests provide important ecosystem services, such as carbon sequestration and soil stabilization. Lidar data measure the three-dimensional structure of forest canopies and are commonly used to quantify aboveground biomass in temperate forest landscapes. However, the ability of lidar data to quantify second growth forest biomass in complex, tropical landscapes is less understood. Our goal was to evaluate the use of airborne lidar data to quantify aboveground biomass in a complex tropical landscape, the Caribbean island of Puerto Rico. Puerto Rico provides an ideal place for studying biomass accumulation because of the abundance of second growth forests in different stages of recovery, and the high ecological heterogeneity. Puerto Rico was almost entirely deforested for agriculture until the 1930s. Thereafter, agricultural abandonment resulted in a mosaic of second growth forests that have recovered naturally under different types of climate, land use, topography, and soil fertility. We integrated forest plot data from the US Forest Service, Forest Inventory and Analysis (FIA) Program with recent lidar data from NASA Goddard's Lidar, Hyperspectral, and Thermal (G-LiHT) airborne imager to quantify forest biomass across the island's landscape. The G-LiHT data consisted on targeted acquisitions over the FIA plots and other forested areas representing the environmental heterogeneity of the island. To fully assess the potential of the lidar data, we compared the ability of lidar-derived canopy metrics to quantify biomass alone, and in combination with intensity and topographic metrics. The results presented here are a key step for improving our understanding of the patterns and drivers of biomass accumulation in tropical forests.

Managing for old-growth forests: a moving target

Treesearch

Thomas A. Spies; Robert J. Pabst

2013-01-01

Presentation Abstract Old-growth Douglas-fi r (Pseudotsuga menziesii) forests are a goal for conservation and restoration across millions of acres of federal forest lands in western Oregon and Washington. Where old growth currently exists, management is typically focused on protecting stands and watersheds from logging and high-severity wildfi re. Where old growth was...

Old-growth forests can accumulate carbon in soils

USGS Publications Warehouse

Zhou, G.; Liu, S.; Li, Z.; Zhang, Dongxiao; Tang, X.; Zhou, C.; Yan, J.; Mo, J.

2006-01-01

Old-growth forests have traditionally been considered negligible as carbon sinks because carbon uptake has been thought to be balanced by respiration. We show that the top 20-centimeter soil layer in preserved old-growth forests in southern China accumulated atmospheric carbon at an unexpectedly high average rate of 0.61 megagrams of carbon hectare-1 year-1 from 1979 to 2003. This study suggests that the carbon cycle processes in the belowground system of these forests are changing in response to the changing environment. The result directly challenges the prevailing belief in ecosystem ecology regarding carbon budget in old-growth forests and supports the establishment of a new, nonequilibrium conceptual framework to study soil carbon dynamics.

Declining Radial Growth Response of Coastal Forests to Hurricanes and Nor'easters

NASA Astrophysics Data System (ADS)

Fernandes, Arnold; Rollinson, Christine R.; Kearney, William S.; Dietze, Michael C.; Fagherazzi, Sergio

2018-03-01

The Mid-Atlantic coastal forests in Virginia are stressed by episodic disturbance from hurricanes and nor'easters. Using annual tree ring data, we adopt a dendroclimatic and statistical modeling approach to understand the response and resilience of a coastal pine forest to extreme storm events, over the past few decades. Results indicate that radial growth of trees in the study area is influenced by age, regional climate trends, and individual tree effects but dominated periodically by growth disturbance due to storms. We evaluated seven local extreme storm events to understand the effect of nor'easters and hurricanes on radial growth. A general decline in radial growth was observed in the year of the extreme storm and 3 years following it, after which the radial growth started recovering. The decline in radial growth showed a statistically significant correlation with the magnitude of the extreme storm (storm surge height and wind speed). This study contributes to understanding declining tree growth response and resilience of coastal forests to past disturbances. Given the potential increase in hurricanes and storm surge severity in the region, this can help predict vegetation response patterns to similar disturbances in the future.

Forest growth in the Douglas fir region.

Treesearch

W.H. Meyer; P.A. Briegleb

1936-01-01

A study of forest growth in western Oregon and western Washington, the so-called Douglas fir region, was made in 1934-35 by the Pacific Northwest Forest Experiment Station. This is one phase of the Nation-wide forest survey undertaken by the Department of Agriculture under authority of the McSweeney-McNary Forest Research Act. Other phases of the survey are an...

Application of a Hybrid Forest Growth Model to Evaluate Climate Change Impacts on Productivity, Nutrient Cycling and Mortality in a Montane Forest Ecosystem

PubMed Central

Seely, Brad; Welham, Clive; Scoullar, Kim

2015-01-01

Climate change introduces considerable uncertainty in forest management planning and outcomes, potentially undermining efforts at achieving sustainable practices. Here, we describe the development and application of the FORECAST Climate model. Constructed using a hybrid simulation approach, the model includes an explicit representation of the effect of temperature and moisture availability on tree growth and survival, litter decomposition, and nutrient cycling. The model also includes a representation of the impact of increasing atmospheric CO2 on water use efficiency, but no direct CO2 fertilization effect. FORECAST Climate was evaluated for its ability to reproduce the effects of historical climate on Douglas-fir and lodgepole pine growth in a montane forest in southern British Columbia, Canada, as measured using tree ring analysis. The model was subsequently used to project the long-term impacts of alternative future climate change scenarios on forest productivity in young and established stands. There was a close association between predicted sapwood production and measured tree ring chronologies, providing confidence that model is able to predict the relative impact of annual climate variability on tree productivity. Simulations of future climate change suggest a modest increase in productivity in young stands of both species related to an increase in growing season length. In contrast, results showed a negative impact on stemwood biomass production (particularly in the case of lodgepole pine) for established stands due to increased moisture stress mortality. PMID:26267446

Understory tree characteristics and disturbance history of a central Appalachian forest prior to old-growth harvesting

Treesearch

Thomas M. Schuler; Mary Ann Fajvan

1999-01-01

To better understand the dynamics of red oak regeneration, we evaluated the composition of understory woody species and recruitment characteristics of a mixed mesophytic forest in the central Appalachian region at the time of old-growth logging. We also evaluated canopy disturbance history during both the old-growth and second-growth periods. Stemwood radial growth...

Climate and Management Controls on Forest Growth and Forest Carbon Balance in the Western United States

NASA Astrophysics Data System (ADS)

Kelsey, Katharine Cashman

Climate change is resulting in a number of rapid changes in forests worldwide. Forests comprise a critical component of the global carbon cycle, and therefore climate-induced changes in forest carbon balance have the potential to create a feedback within the global carbon cycle and affect future trajectories of climate change. In order to further understanding of climate-driven changes in forest carbon balance, I (1) develop a method to improve spatial estimates forest carbon stocks, (2) investigate the effect of climate change and forest management actions on forest recovery and carbon balance following disturbance, and (3) explore the relationship between climate and forest growth, and identify climate-driven trends in forest growth through time, within San Juan National Forest in southwest Colorado, USA. I find that forest carbon estimates based on texture analysis from LandsatTM imagery improve regional forest carbon maps, and this method is particularly useful for estimating carbon stocks in forested regions affected by disturbance. Forest recovery from disturbance is also a critical component of future forest carbon stocks, and my results indicate that both climate and forest management actions have important implications for forest recovery and carbon dynamics following disturbance. Specifically, forest treatments that use woody biomass removed from the forest for electricity production can reduce carbon emissions to the atmosphere, but climate driven changes in fire severity and forest recovery can have the opposite effect on forest carbon stocks. In addition to the effects of disturbance and recovery on forest condition, I also find that climate change is decreasing rates of forest growth in some species, likely in response to warming summer temperatures. These growth declines could result in changes of vegetation composition, or in extreme cases, a shift in vegetation type that would alter forest carbon storage. This work provides insight into both

Cutting a young-growth, mixed-conifer stand to California Forest Practice Act Standards

Treesearch

Philip M. McDonald

1973-01-01

Cutting by the minimum standard of the Rules of California's North Sierra Pine Forest District was evaluated for effects on species composition, seed fall, regeneration, and residual growth at the Challenge Experimental Forest, central California. Cutting removed 74 percent of the stand basal area and 94 percent of the merchantable volume. The heavy cut changed...

Ninety-two years of tree growth and death in a second-growth redwood forest

Treesearch

Benjamin G. Iberle; Stephen C. Sillett; Robert Van Pelt; Mark Andre

2017-01-01

Mature second-growth redwood (Sequoia sempervirens (D. Don) Endl.) forests are an important and uncommon resource in the redwood region. Development of second-growth redwood forests beyond rotation age is not well understood. Continuous long-term data are especially lacking, considering that the maximum possible age of second-growth stands is now...

Multicriteria evaluation of simulated logging scenarios in a tropical rain forest.

PubMed

Huth, Andreas; Drechsler, Martin; Köhler, Peter

2004-07-01

Forest growth models are useful tools for investigating the long-term impacts of logging. In this paper, the results of the rain forest growth model FORMIND were assessed by a multicriteria decision analysis. The main processes covered by FORMIND include tree growth, mortality, regeneration and competition. Tree growth is calculated based on a carbon balance approach. Trees compete for light and space; dying large trees fall down and create gaps in the forest. Sixty-four different logging scenarios for an initially undisturbed forest stand at Deramakot (Malaysia) were simulated. The scenarios differ regarding the logging cycle, logging method, cutting limit and logging intensity. We characterise the impacts with four criteria describing the yield, canopy opening and changes in species composition. Multicriteria decision analysis was used for the first time to evaluate the scenarios and identify the efficient ones. Our results plainly show that reduced-impact logging scenarios are more 'efficient' than the others, since in these scenarios forest damage is minimised without significantly reducing yield. Nevertheless, there is a trade-off between yield and achieving a desired ecological state of logged forest; the ecological state of the logged forests can only be improved by reducing yields and enlarging the logging cycles. Our study also demonstrates that high cutting limits or low logging intensities cannot compensate for the high level of damage caused by conventional logging techniques.

DRAINMOD-FOREST: Integrated modeling of hydrology, soil carbon and nitrogen dynamics, and plant growth for drained forests

Treesearch

Shiying Tian; Mohamed A. Youssef; R. Wayne Skaggs; Devendra M. Amatya; G.M. Chescheir

2012-01-01

We present a hybrid and stand-level forest ecosystem model, DRAINMOD-FOREST, for simulating the hydrology, carbon (C) and nitrogen (N) dynamics, and tree growth for drained forest lands under common silvicultural practices. The model was developed by linking DRAINMOD, the hydrological model, and DRAINMOD-N II, the soil C and N dynamics model, to a forest growth model,...

Drought as a driver of declining boreal forest growth: Integrating forest inventory measurements with models to gain insight into underlying mechanisms

NASA Astrophysics Data System (ADS)

Trugman, A. T.; Medvigy, D.; Anderegg, W.; Caspersen, J.; Zeng, H.; Pacala, S. W.

2016-12-01

Boreal forests contain over 30% of Earth's terrestrial carbon and are an important component of the land carbon sink. However, the future ability of the boreal forest to maintain a net carbon sink is uncertain and depends on potentially compensating interactions of CO2 fertilization, warmer temperatures, and hotter drought conditions. Observational studies have attributed drought as a major driver of recent declines in growth and increases in mortality in many parts of the North American boreal forest. Yet, most vegetation models have a simplistic representation of vegetation water stress and fail to capture drought-associated growth and mortality trends, impacting our ability to accurately forecast the effects of climate change on the boreal forest. Here, we show additional evidence for widespread declines in boreal tree growth and increasing insect-related mortality in aspen trees based on a mixed model analysis of the Cooperative Alaska Forest Inventory. Our findings indicate that the growth decline is controlled by high midsummer potential evapotranspiration that overpowers any CO2 fertilization signal. We also observe a possible shift in the distribution of angiosperm and gymnosperm, a biological transition that could impact long-term local carbon dynamics. Using insight gained from our mixed model analysis, we perform a regional-scale model evaluation using the boreal forest version of Ecosystem Demography model 2 that includes a dynamic soil organic layer, 7 boreal-specific plant functional types, and a fully mechanistic plant hydraulic scheme. We then use both the Alaskan and Canadian Forest Inventories to constrain our hypotheses and assess whether drought related growth declines can be better attributed to tree drought response from (1) carbon starvation, (2) permanent damage of hydraulic machinery, or (3) delayed recovery of hydraulic machinery. Under each of these scenarios we forecast how drought potentially impacts decadal-scale boreal carbon dynamics.

Late-successional and old-growth forest effectiveness monitoring plan for the Northwest Forest Plan.

Treesearch

Miles Hemstrom; Thomas Spies; Craig Palmer; Ross Kiester; John Teply; Phil McDonald; Ralph. Warbington

1998-01-01

This report presents options for long-term effectiveness monitoring of late-successional and old-growth forests under the Northwest Forest Plan. It describes methods to answer questions about how much late-successional forest exists on Federal land, its pattern, how it’s changing, and if the Forest Plan is providing for its conservation and management. It specifies...

Area of old-growth forests in California, Oregon, and Washington.

Treesearch

Charles L. Bolsinger; Karen L. Waddell

1993-01-01

Area of old-growth forests in California, Oregon, and Washington has declined significantly in the second half of the 20th century. This report summarizes available information on old-growth forest area by ownership in California, Oregon, and Washington. Old-growth definitions used by the various owners and agencies are provided.

Contrasting growth phenology of native and invasive forest shrubs mediated by genome size.

PubMed

Fridley, Jason D; Craddock, Alaä

2015-08-01

Examination of the significance of genome size to plant invasions has been largely restricted to its association with growth rate. We investigated the novel hypothesis that genome size is related to forest invasions through its association with growth phenology, as a result of the ability of large-genome species to grow more effectively through cell expansion at cool temperatures. We monitored the spring leaf phenology of 54 species of eastern USA deciduous forests, including native and invasive shrubs of six common genera. We used new measurements of genome size to evaluate its association with spring budbreak, cell size, summer leaf production rate, and photosynthetic capacity. In a phylogenetic hierarchical model that differentiated native and invasive species as a function of summer growth rate and spring budbreak timing, species with smaller genomes exhibited both faster growth and delayed budbreak compared with those with larger nuclear DNA content. Growth rate, but not budbreak timing, was associated with whether a species was native or invasive. Our results support genome size as a broad indicator of the growth behavior of woody species. Surprisingly, invaders of deciduous forests show the same small-genome tendencies of invaders of more open habitats, supporting genome size as a robust indicator of invasiveness. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Capturing Old-Growth Values for Use in Forest Decision-Making

NASA Astrophysics Data System (ADS)

Owen, Rochelle J.; Duinker, Peter N.; Beckley, Thomas M.

2009-02-01

Old-growth forests have declined significantly across the world. Decisions related to old growth are often mired in challenges of value diversity, conflict, data gaps, and resource pressures. This article describes old-growth values of citizens and groups in Nova Scotia, Canada, for integration in sustainable forest management (SFM) decision-making. The study is based on data from 76 research subjects who participated in nine field trips to forest stands. Research subjects were drawn from Aboriginal groups, environmental organizations, forestry professionals, and rural and urban publics. Diaries, group discussions, and rating sheets were used to elicit information during the field trips. Findings show that different elicitation techniques can influence the articulation of intensity with which some values are held. In addition, certain values are more often associated with old-growth than with other forest-age classes. Some values associated with old-growth are considered more important than others, and some silvicultural treatments are perceived to compromise old-growth values more than others. Demographic characteristics, such as constituency group, gender, and age, are shown to influence value priorities. Ideas on how to incorporate old-growth values into SFM decision-making are highlighted.

An Old-Growth Definition for Southern Mixed Hardwood Forests

Treesearch

William B. Batista; William J. Platt

1997-01-01

This report provides an old-growth definition for the southern mixed hardwood forests based on five exemplary stands that show no evidence of having undergone any natural catastrophe or clearcutting for at least 200 years. This forest type occurs in the U.S. southeastern Coastal Plain from the Carolinas to eastern Texas. The exemplary old-growth stands were restricted...

Complementary models of tree species-soil relationships in old-growth temperate forests

USGS Publications Warehouse

Cross, Alison; Perakis, Steven S.

2011-01-01

Ecosystem level studies identify plant soil feed backs as important controls on soil nutrient availability,particularly for nitrogen and phosphorus. Although site and species specific studies of tree species soil relationships are relatively common,comparatively fewer studies consider multiple coexisting speciesin old-growth forests across a range of sites that vary underlying soil fertility. We characterized patterns in forest floor and mineral soil nutrients associated with four common tree species across eight undisturbed old-growth forests in Oregon, USA, and used two complementary conceptual models to assess tree species soil relationships. Plant soil feedbacks that could reinforce sitelevel differences in nutrient availability were assessed using the context dependent relationships model, where by relative species based differences in each soil nutrient divergedorconvergedas nutrient status changed across sites. Tree species soil relationships that did not reflect strong feedbacks were evaluated using a site independent relationships model, where by forest floor and surface mineral soil nutrient tools differed consistently by tree species across sites,without variation in deeper mineral soils. We found that theorganically cycled elements carbon, nitrogen, and phosphorus exhibited context-dependent differences among species in both forest floor and mineral soil, and most of ten followed adivergence model,where by species differences were greatest at high-nutrient sites. These patterns are consistent with the oryemphasizing biotic control of these elements through plant soil feedback mechanisms. Site independent species differences were strongest for pool so if the weather able cations calcium, magnesium, potassium,as well as phosphorus, in mineral soils. Site independent species differences in forest floor nutrients we reattributable too nespecies that displayed significant greater forest floor mass accumulation. Our finding confirmed that site-independent and

Climate-driven speedup of alpine treeline forest growth in the Tianshan Mountains, Northwestern China.

PubMed

Qi, Zhaohuan; Liu, Hongyan; Wu, Xiuchen; Hao, Qian

2015-02-01

Forest growth is sensitive to interannual climatic change in the alpine treeline ecotone (ATE). Whether the alpine treeline ecotone shares a similar pattern of forest growth with lower elevational closed forest belt (CFB) under changing climate remains unclear. Here, we reported an unprecedented acceleration of Picea schrenkiana forest growth since 1960s in the ATE of Tianshan Mountains, northwestern China by a stand-total sampling along six altitudinal transects with three plots in each transect: one from the ATE between the treeline and the forest line, and the other two from the CFB. All the sampled P. schrenkiana forest patches show a higher growth speed after 1960 and, comparatively, forest growth in the CFB has sped up much slower than that in the ATE. The speedup of forest growth at the ATE is mainly accounted for by climate factors, with increasing temperature suggested to be the primary driver. Stronger water deficit as well as more competition within the CFB might have restricted forest growth there more than that within the ATE, implying biotic factors were also significant for the accelerated forest growth in the ATE, which should be excluded from simulations and predictions of warming-induced treeline dynamics. © 2014 John Wiley & Sons Ltd.

Carbon storage in old-growth forests of the Mid-Atlantic: toward better understanding the eastern forest carbon sink.

PubMed

McGarvey, Jennifer C; Thompson, Jonathan R; Epstein, Howard E; Shugart, Herman H

2015-02-01

Few old-growth stands remain in the matrix of secondary forests that dominates the eastern North American landscape. These remnant stands offer insight on the potential carbon (C) storage capacity of now-recovering secondary forests. We surveyed the remaining old-growth forests on sites characteristic of the general Mid-Atlantic United States and estimated the size of multiple components of forest C storage. Within and between old-growth stands, variability in C density is high and related to overstory tree species composition. The sites contain 219 ± 46 Mg C/ha (mean ± SD), including live and dead aboveground biomass, leaf litter, and the soil O horizon, with over 20% stored in downed wood and snags. Stands dominated by tulip poplar (Liriodendron tulipifera) store the most live biomass, while the mixed oak (Quercus spp.) stands overall store more dead wood. Total C density is 30% higher (154 Mg C/ha), and dead wood C density is 1800% higher (46 Mg C/ha) in the old-growth forests than in the surrounding younger forests (120 and 5 Mg C/ha, respectively). The high density of dead wood in old growth relative to secondary forests reflects a stark difference in historical land use and, possibly, the legacy of the local disturbance (e.g., disease) history. Our results demonstrate the potential for dead wood to maintain the sink capacity of secondary forests for many decades to come.

Midcanopy growth following thinning in young-growth conifer forests on the Olympic Peninsula, western Washington

Treesearch

Emily J. Comfort; Scott D. Roberts; Constance A. Harrington

2010-01-01

Midcanopy layers are essential structures in "old-growth" forests on the Olympic Peninsula. Little is known about which stand and tree factors influence the ability of midcanopy trees in young-growth forests to respond to release; however, this information is important to managers interested in accelerating development of late-successional structural...

Adjusting the Stems Regional Forest Growth Model to Improve Local Predictions

Treesearch

W. Brad Smith

1983-01-01

A simple procedure using double sampling is described for adjusting growth in the STEMS regional forest growth model to compensate for subregional variations. Predictive accuracy of the STEMS model (a distance-independent, individual tree growth model for Lake States forests) was improved by using this procedure

Forest stand growth dynamics in Central Europe have accelerated since 1870

PubMed Central

Pretzsch, Hans; Biber, Peter; Schütze, Gerhard; Uhl, Enno; Rötzer, Thomas

2014-01-01

Forest ecosystems have been exposed to climate change for more than 100 years, whereas the consequences on forest growth remain elusive. Based on the oldest existing experimental forest plots in Central Europe, we show that, currently, the dominant tree species Norway spruce and European beech exhibit significantly faster tree growth (+32 to 77%), stand volume growth (+10 to 30%) and standing stock accumulation (+6 to 7%) than in 1960. Stands still follow similar general allometric rules, but proceed more rapidly through usual trajectories. As forest stands develop faster, tree numbers are currently 17–20% lower than in past same-aged stands. Self-thinning lines remain constant, while growth rates increase indicating the stock of resources have not changed, while growth velocity and turnover have altered. Statistical analyses of the experimental plots, and application of an ecophysiological model, suggest that mainly the rise in temperature and extended growing seasons contribute to increased growth acceleration, particularly on fertile sites. PMID:25216297

Growth of Secondary Forest in Puerto Rico Between 1980 and 1985.

Treesearch

P. L. Weaver; R. A. Birdsey

1990-01-01

Successive inventories in Puerto Rico provided the first estimates of secondary forest growth on a regional basis. The volume of growing stock trees increased by 32%, and timber volume by nearly 36%, on all classes of forest land between 1980 and 198.5. Timber volume growth rates (in m’ha-’ yr-’ ) varied by forest class and averaged 2.0 in young secondary forest, 6.9...

Updating Indiana Annual Forest Inventory and Analysis Plot Data Using Eastern Broadleaf Forest Diameter Growth Models

Treesearch

Veronica C. Lessard

2001-01-01

The Forest Inventory and Analysis (FIA) program of the North Central Research Station (NCRS), USDA Forest Service, has developed nonlinear, individual-tree, distance-independent annual diameter growth models. The models are calibrated for species groups and formulated as the product of an average diameter growth component and a modifier component. The regional models...

Liana infestation impacts tree growth in a lowland tropical moist forest

NASA Astrophysics Data System (ADS)

van der Heijden, G. M. F.; Phillips, O. L.

2009-03-01

Stand-level estimates of the effect of lianas on tree growth in mature tropical forests are needed to evaluate the functional impact of lianas and their potential to affect the ability of tropical forests to sequester carbon, but these are currently lacking. Using data collected on tree growth rates, local growing conditions and liana competition in five permanent sampling plots in Amazonian Peru, we present the first such estimates of the effect of lianas on above-ground productivity of trees. By constructing a multi-level linear mixed effect model to predict individual tree diameter growth model using individual tree growth conditions, we were able to estimate stand-level above-ground biomass (AGB) increment in the absence of lianas. We show that lianas, mainly by competing above-ground with trees, reduce tree annual above-ground stand-level biomass by ~10%, equivalent to 0.51 Mg dry weight ha-1 yr-1 or 0.25 Mg C ha-1 yr-1. AGB increment of lianas themselves was estimated to be 0.15 Mg dry weight ha-1 yr-1 or 0.07 Mg C ha-1 yr-1, thus only compensating ~29% of the liana-induced reduction in stand-level AGB increment. Increasing liana pressure on tropical forests may therefore not only reduce their carbon storage capacity, by indirectly promoting tree species with low-density wood, but also their rate of carbon uptake, with potential consequences for the rate of increase in atmospheric carbon dioxide.

Short-term effects of experimental burning and thinning on soil respiration in an old-growth, mixed-conifer forest

Treesearch

Siyan Ma; Jiquan Chen; Malcolm North; Heather E. Erickson; Mary Bresee; James Le Moine

2004-01-01

To understand the roles of forest management practices in meeting the goals of forest sustainability and CO2 sequestration, we evaluated the effects of burning and thinning treatments on soil respiration and soil environments in an old-growth, mixed-conifer forest in California’s southern Sierra Nevada. Six experimental treatments with two levels...

Characterization of an Old-Growth Forest in the Cross Timbers of Oklahoma

Treesearch

S.L. Clark; S.W. Hallgren

2004-01-01

Many cross timbers forests in central Oklahoma were neither extensively logged nor farmed and may contain some of the largest tracts of old-growth forests, particularly those dominated by oak, in eastern North America (Therrell and Stahle 1998). We studied a 90 ha old-growth forest in Osage County, Oklahoma which is one of the few designated forest preserves in the...

Structural and compositional differences between old-growth and mature second-growth forests in the Missouri Ozarks

Treesearch

Stephen R. Shifley; Lynn M. Roovers; Brian L. Brookshire

1995-01-01

There are currently only about 7,900 acres (3,200 ha) of remnant old-growth forest in Missouri, but public land management plans call for old-growth acreage to increase to more than 200,000 acres (81,000 ha). To develop a better quantitative understanding of the transitions that are likely as current forests mature to an old-growth state, we compared a number of...

An individual-based growth and competition model for coastal redwood forest restoration

USGS Publications Warehouse

van Mantgem, Phillip J.; Das, Adrian J.

2014-01-01

Thinning treatments to accelerate coastal redwood forest stand development are in wide application, but managers have yet to identify prescriptions that might best promote Sequoia sempervirens (Lamb. ex D. Don) Endl. (redwood) growth. The creation of successful thinning prescriptions would be aided by identifying the underlying mechanisms governing how individual tree growth responds to competitive environments in coastal redwood forests. We created a spatially explicit individual-based model of tree competition and growth parameterized using surveys of upland redwood forests at Redwood National Park, California. We modeled competition for overstory trees (stems ≥ 20 cm stem diameter at breast height, 1.37 m (dbh)) as growth reductions arising from sizes, distances, and species identity of competitor trees. Our model explained up to half of the variation in individual tree growth, suggesting that neighborhood crowding is an important determinant of growth in this forest type. We used our model to simulate the effects of novel thinning prescriptions (e.g., 40% stand basal area removal) for redwood forest restoration, concluding that these treatments could lead to substantial growth releases, particularly for S. sempervirens. The results of this study, along with continued improvements to our model, will help to determine spacing and species composition that best encourage growth.

Converging Climate Sensitivities of European Forests Between Observed Radial Tree Growth and Vegetation Models

NASA Technical Reports Server (NTRS)

Zhang, Zhen; Babst, Flurin; Bellassen, Valentin; Frank, David; Launois, Thomas; Tan, Kun; Ciais, Philippe; Poulter, Benjamin

2017-01-01

The impacts of climate variability and trends on European forests are unevenly distributed across different bioclimatic zones and species. Extreme climate events are also becoming more frequent and it is unknown how they will affect feed backs of CO2 between forest ecosystems and the atmosphere. An improved understanding of species differences at the regional scale of the response of forest productivity to climate variation and extremes is thus important for forecasting forest dynamics. In this study, we evaluate the climate sensitivity of above ground net primary production (NPP) simulated by two dynamic global vegetation models (DGVM; ORCHIDEE and LPJ-wsl) against tree ring width (TRW) observations from about1000 sites distributed across Europe. In both the model simulations and the TRW observations, forests in northern Europe and the Alps respond positively to warmer spring and summer temperature, and their overall temperature sensitivity is larger than that of the soil-moisture-limited forests in central Europe and Mediterranean regions. Compared with TRW observations, simulated NPP from ORCHIDEE and LPJ-wsl appear to be overly sensitive to climatic factors. Our results indicate that the models lack biological processes that control time lags, such as carbohydrate storage and remobilization, that delay the effects of radial growth dynamics to climate. Our study highlights the need for re-evaluating the physiological controls on the climate sensitivity of NPP simulated by DGVMs. In particular, DGVMs could be further enhanced by a more detailed representation of carbon reserves and allocation that control year-to year variation in plant growth.

Prioritizing treatment of second-growth forests using LiDAR

Treesearch

Lathrop P. Leonard; Daryl Van Dyke

2012-01-01

We used multi-return light detecting and ranging (LiDAR) to develop a costeffective method for describing forest conditions and prioritizing stands for treatment in over 14,000 ha of second-growth forests (11 to 85 years old) in Del Norte Coast Redwoods State Park (DNCRSP). DNCRSP consists primarily of redwood and Douglas-fir dominated forests with scattered tanoak...

Information system of forest growth and productivity by site quality type and elements of forest

NASA Astrophysics Data System (ADS)

Khlyustov, V.

2012-04-01

Information system of forest growth and productivity by site quality type and elements of forest V.K. Khlustov Head of the Forestry Department of Russian State Agrarian University named after K.A.Timiryazev doctor of agricultural sciences, professor The efficiency of forest management can be improved substantially by development and introduction of principally new models of forest growth and productivity dynamics based on regionalized site specific parameters. Therefore an innovative information system was developed. It describes the current state and gives a forecast for forest stand parameters: growth, structure, commercial and biological productivity depend on type of site quality. In contrast to existing yield tables, the new system has environmental basis: site quality type. The information system contains set of multivariate statistical models and can work at the level of individual trees or at the stand level. The system provides a graphical visualization, as well as export of the emulation results. The System is able to calculate detailed description of any forest stand based on five initial indicators: site quality type, site index, stocking, composition, and tree age by elements of the forest. The results of the model run are following parameters: average diameter and height, top height, number of trees, basal area, growing stock (total, commercial with distribution by size, firewood and residuals), live biomass (stem, bark, branches, foliage). The system also provides the distribution of mentioned above forest stand parameters by tree diameter classes. To predict the future forest stand dynamics the system require in addition the time slot only. Full set of forest parameters mention above will be provided by the System. The most conservative initial parameters (site quality type and site index) can be kept in the form of geo referenced polygons. In this case the system would need only 3 dynamic initial parameters (stocking, composition and age) to

An Old-Growth Definition for Western and Mixed Mesophytic Forests

Treesearch

Cathryn H. Greenberg; Donald E. McLeod; David L. Loftis

1997-01-01

Old growth is widely acknowledged today as an essential part of managed forests, particularly on public lands. However, this concept is relatively new, evolving since the 1970's when a grassroots movement in the Pacific Northwest began in earnest to define old growth. In response to changes in public attitude, the U.S. Department of Agriculture, Forest Service,...

Adjusting STEMS growth model for Wisconsin forests.

Treesearch

Margaret R. Holdaway

1985-01-01

Describes a simple procedure for adjusting growth in the STEMS regional tree growth model to compensate for subregional differences. Coefficients are reported to adjust Lake States STEMS to the forests of Northern and Central Wisconsin--an area of essentially uniform climate and similar broad physiographic features. Errors are presented for various combinations of...

Old-growth and mature forests near spotted owl nests in western Oregon

NASA Technical Reports Server (NTRS)

Ripple, William J.; Johnson, David H.; Hershey, K. T.; Meslow, E. Charles

1995-01-01

We investigated how the amount of old-growth and mature forest influences the selection of nest sites by northern spotted owls (Strix occidentalis caurina) in the Central Cascade Mountains of Oregon. We used 7 different plot sizes to compare the proportion of mature and old-growth forest between 30 nest sites and 30 random sites. The proportion of old-growth and mature forest was significantly greater at nests sites than at random sites for all plot sizes (P less than or equal to 0.01). Thus, management of the spotted owl might require setting the percentage of old-growth and mature forest retained from harvesting at least 1 standard deviation above the mean for the 30 nest sites we examined.

Liana infestation impacts tree growth in a lowland tropical moist forest

NASA Astrophysics Data System (ADS)

van der Heijden, G. M. F.; Phillips, O. L.

2009-10-01

Ecosystem-level estimates of the effect of lianas on tree growth in mature tropical forests are needed to evaluate the functional impact of lianas and their potential to affect the ability of tropical forests to sequester carbon, but these are currently lacking. Using data collected on tree growth rates, local growing conditions and liana competition in five permanent sampling plots in Amazonian Peru, we present the first ecosystem-level estimates of the effect of lianas on above-ground productivity of trees. By first constructing a multi-level linear mixed effect model to predict individual-tree diameter growth model using individual-tree growth conditions, we were able to then estimate stand-level above-ground biomass (AGB) increment in the absence of lianas. We show that lianas, mainly by competing above-ground with trees, reduce tree annual above-ground stand-level biomass increment by ~10%, equivalent to 0.51 Mg dry weight ha-1 yr-1 or 0.25 Mg C ha-1 yr-1. AGB increment of lianas themselves was estimated to be 0.15 Mg dry weight ha-1 yr-1 or 0.07 Mg C ha-1 yr-1, thus only compensating ~29% of the liana-induced reduction in ecosystem AGB increment. Increasing liana pressure on tropical forests will therefore not only tend to reduce their carbon storage capacity, by indirectly promoting tree species with low-density wood, but also their rate of carbon uptake, with potential consequences for the rate of increase in atmospheric carbon dioxide.

Historical harvests reduce neighboring old-growth basal area across a forest landscape.

PubMed

Bell, David M; Spies, Thomas A; Pabst, Robert

2017-07-01

While advances in remote sensing have made stand, landscape, and regional assessments of the direct impacts of disturbance on forests quite common, the edge influence of timber harvesting on the structure of neighboring unharvested forests has not been examined extensively. In this study, we examine the impact of historical timber harvests on basal area patterns of neighboring old-growth forests to assess the magnitude and scale of harvest edge influence in a forest landscape of western Oregon, USA. We used lidar data and forest plot measurements to construct 30-m resolution live tree basal area maps in lower and middle elevation mature and old-growth forests. We assessed how edge influence on total, upper canopy, and lower canopy basal area varied across this forest landscape as a function of harvest characteristics (i.e., harvest size and age) and topographic conditions in the unharvested area. Upper canopy, lower canopy, and total basal area increased with distance from harvest edge and elevation. Forests within 75 m of harvest edges (20% of unharvested forests) had 4% to 6% less live tree basal area compared with forest interiors. An interaction between distance from harvest edge and elevation indicated that elevation altered edge influence in this landscape. We observed a positive edge influence at low elevations (<800 m) and a negative edge influence at moderate to high elevations (>800 m). Surprisingly, we found no or weak effects of harvest age (13-60 yr) and harvest area (0.2-110 ha) on surrounding unharvested forest basal area, implying that edge influence was relatively insensitive to the scale of disturbance and multi-decadal recovery processes. Our study indicates that the edge influence of past clearcutting on the structure of neighboring uncut old-growth forests is widespread and persistent. These indirect and diffuse legacies of historical timber harvests complicate forest management decision-making in old-growth forest landscapes by broadening

An Old-Growth Definition for Southwestern Subtropical Upland Forests

Treesearch

David D. Diamond

1998-01-01

Mainly evergreen, broad-leaved forests in the Southwestern United States are restricted to the Lower Rio Grande Valley of Texas. The soils and long growing season make this region valuable cropland, and, thus, almost all of the area once occupied by this forest type has been converted to row crops. Remaining old-growth forests are usually dominated by some combination...

Old forests and endangered woodpeckers: old-growth in the Southern Coastal Plain

Treesearch

Robert Mitchell; Todd Engstrom; Rebecca Sharitz; Diane De Steven; Kevin Hiers; Robert Cooper; Katherine. Kirkman

2009-01-01

Southern old-growth forests are small and rare, but critical in their support of biodiversity. While the remnant old-growth forests contain diversity that is significant regionally and globally, they most likely represent only a portion of the variety that old forests once sustained. High within-habitat diversity and rarity in the landscape magnify the conservation...

Remnant trees affect species composition but not structure of tropical second-growth forest.

PubMed

Sandor, Manette E; Chazdon, Robin L

2014-01-01

Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2-3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests ("control plots"). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields.

Changes in conifer and deciduous forest foliar and forest floor chemistry and basal area tree growth across a nitrogen (N) deposition gradient in the northeastern US

Treesearch

Johnny L. Boggs; Steven G. McNulty; Linda H. Pardo

2007-01-01

We evaluated foliar and forest floor chemistry across a gradient of N deposition in the Northeast at 11 red spruce (Picea rubens Sarg.) sites in 1987/1988 and foliar and forest floor chemistry and basal area growth at six paired spruce and deciduous sites in 1999. The six red spruce plots were a subset of the original 1987/1988 spruce sites. In 1999...

Growth decline linked to warming-induced water limitation in hemi-boreal forests.

PubMed

Wu, Xiuchen; Liu, Hongyan; Guo, Dali; Anenkhonov, Oleg A; Badmaeva, Natalya K; Sandanov, Denis V

2012-01-01

Hemi-boreal forests, which make up the transition from temperate deciduous forests to boreal forests in southern Siberia, have experienced significant warming without any accompanying increase in precipitation during the last 80 years. This climatic change could have a profound impact on tree growth and on the stability of forest ecosystems in this region, but at present evidence for these impacts is lacking. In this study, we report a recent dramatic decline in the growth of hemi-boreal forests, based on ring width measurements from three dominant tree-species (Pinus sylvestris, Larix sibirica and Larix gmelinii), sampled from eight sites in the region. We found that regional tree growth has become increasingly limited by low soil water content in the pre- and early-growing season (from October of the previous year to July of the current year) over the past 80 years. A warming-induced reduction in soil water content has also increased the climate sensitivity of these three tree species. Beginning in the mid-1980s, a clear decline in growth is evident for both the pine forests and the larch forests, although there are increasing trends in the proxy of soil water use efficiencies. Our findings are consistent with those from other parts of the world and provide valuable insights into the regional carbon cycle and vegetation dynamics, and should be useful for devising adaptive forest management strategies.

Winter climate limits subantarctic low forest growth and establishment.

PubMed

Harsch, Melanie A; McGlone, Matt S; Wilmshurst, Janet M

2014-01-01

Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E) is oceanic (Conrad Index of Continentality  =  -5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

Spatial aspects of tree mortality strongly differ between young and old-growth forests.

PubMed

Larson, Andrew J; Lutz, James A; Donato, Daniel C; Freund, James A; Swanson, Mark E; HilleRisLambers, Janneke; Sprugel, Douglas G; Franklin, Jerry F

2015-11-01

Rates and spatial patterns of tree mortality are predicted to change during forest structural development. In young forests, mortality should be primarily density dependent due to competition for light, leading to an increasingly spatially uniform pattern of surviving trees. In contrast, mortality in old-growth forests should be primarily caused by contagious and spatially autocorrelated agents (e.g., insects, wind), causing spatial aggregation of surviving trees to increase through time. We tested these predictions by contrasting a three-decade record of tree mortality from replicated mapped permanent plots located in young (< 60-year-old) and old-growth (> 300-year-old) Abies amabilis forests. Trees in young forests died at a rate of 4.42% per year, whereas trees in old-growth forests died at 0.60% per year. Tree mortality in young forests was significantly aggregated, strongly density dependent, and caused live tree patterns to become more uniform through time. Mortality in old-growth forests was spatially aggregated, but was density independent and did not change the spatial pattern of surviving trees. These results extend current theory by demonstrating that density-dependent competitive mortality leading to increasingly uniform tree spacing in young forests ultimately transitions late in succession to a more diverse tree mortality regime that maintains spatial heterogeneity through time.

A Novel Modelling Approach for Predicting Forest Growth and Yield under Climate Change.

PubMed

Ashraf, M Irfan; Meng, Fan-Rui; Bourque, Charles P-A; MacLean, David A

2015-01-01

Global climate is changing due to increasing anthropogenic emissions of greenhouse gases. Forest managers need growth and yield models that can be used to predict future forest dynamics during the transition period of present-day forests under a changing climatic regime. In this study, we developed a forest growth and yield model that can be used to predict individual-tree growth under current and projected future climatic conditions. The model was constructed by integrating historical tree growth records with predictions from an ecological process-based model using neural networks. The new model predicts basal area (BA) and volume growth for individual trees in pure or mixed species forests. For model development, tree-growth data under current climatic conditions were obtained using over 3000 permanent sample plots from the Province of Nova Scotia, Canada. Data to reflect tree growth under a changing climatic regime were projected with JABOWA-3 (an ecological process-based model). Model validation with designated data produced model efficiencies of 0.82 and 0.89 in predicting individual-tree BA and volume growth. Model efficiency is a relative index of model performance, where 1 indicates an ideal fit, while values lower than zero means the predictions are no better than the average of the observations. Overall mean prediction error (BIAS) of basal area and volume growth predictions was nominal (i.e., for BA: -0.0177 cm(2) 5-year(-1) and volume: 0.0008 m(3) 5-year(-1)). Model variability described by root mean squared error (RMSE) in basal area prediction was 40.53 cm(2) 5-year(-1) and 0.0393 m(3) 5-year(-1) in volume prediction. The new modelling approach has potential to reduce uncertainties in growth and yield predictions under different climate change scenarios. This novel approach provides an avenue for forest managers to generate required information for the management of forests in transitional periods of climate change. Artificial intelligence technology

A Novel Modelling Approach for Predicting Forest Growth and Yield under Climate Change

PubMed Central

Ashraf, M. Irfan; Meng, Fan-Rui; Bourque, Charles P.-A.; MacLean, David A.

2015-01-01

Global climate is changing due to increasing anthropogenic emissions of greenhouse gases. Forest managers need growth and yield models that can be used to predict future forest dynamics during the transition period of present-day forests under a changing climatic regime. In this study, we developed a forest growth and yield model that can be used to predict individual-tree growth under current and projected future climatic conditions. The model was constructed by integrating historical tree growth records with predictions from an ecological process-based model using neural networks. The new model predicts basal area (BA) and volume growth for individual trees in pure or mixed species forests. For model development, tree-growth data under current climatic conditions were obtained using over 3000 permanent sample plots from the Province of Nova Scotia, Canada. Data to reflect tree growth under a changing climatic regime were projected with JABOWA-3 (an ecological process-based model). Model validation with designated data produced model efficiencies of 0.82 and 0.89 in predicting individual-tree BA and volume growth. Model efficiency is a relative index of model performance, where 1 indicates an ideal fit, while values lower than zero means the predictions are no better than the average of the observations. Overall mean prediction error (BIAS) of basal area and volume growth predictions was nominal (i.e., for BA: -0.0177 cm2 5-year-1 and volume: 0.0008 m3 5-year-1). Model variability described by root mean squared error (RMSE) in basal area prediction was 40.53 cm2 5-year-1 and 0.0393 m3 5-year-1 in volume prediction. The new modelling approach has potential to reduce uncertainties in growth and yield predictions under different climate change scenarios. This novel approach provides an avenue for forest managers to generate required information for the management of forests in transitional periods of climate change. Artificial intelligence technology has substantial

Communicating old-growth forest management on the Allegheny National Forest

Treesearch

Brad Nelson; Chris Nowak; Dave deCalesta; Steve Wingate

1997-01-01

Successful communication of old-growth management, including the role of silviculture, is achieved by integrating as a working whole the topics addressed in this workshop. We have used research, technology transfer and adaptive management to achieve this integration on the Allegheny National Forest. Program success depends on scientists and practitioners working...

Remnant Trees Affect Species Composition but Not Structure of Tropical Second-Growth Forest

PubMed Central

Sandor, Manette E.; Chazdon, Robin L.

2014-01-01

Remnant trees, spared from cutting when tropical forests are cleared for agriculture or grazing, act as nuclei of forest regeneration following field abandonment. Previous studies on remnant trees were primarily conducted in active pasture or old fields abandoned in the previous 2–3 years, and focused on structure and species richness of regenerating forest, but not species composition. Our study is among the first to investigate the effects of remnant trees on neighborhood forest structure, biodiversity, and species composition 20 years post-abandonment. We compared the woody vegetation around individual remnant trees to nearby plots without remnant trees in the same second-growth forests (“control plots”). Forest structure beneath remnant trees did not differ significantly from control plots. Species richness and species diversity were significantly higher around remnant trees. The species composition around remnant trees differed significantly from control plots and more closely resembled the species composition of nearby old-growth forest. The proportion of old-growth specialists and generalists around remnant trees was significantly greater than in control plots. Although previous studies show that remnant trees may initially accelerate secondary forest growth, we found no evidence that they locally affect stem density, basal area, and seedling density at later stages of regrowth. Remnant trees do, however, have a clear effect on the species diversity, composition, and ecological groups of the surrounding woody vegetation, even after 20 years of forest regeneration. To accelerate the return of diversity and old-growth forest species into regrowing forest on abandoned land, landowners should be encouraged to retain remnant trees in agricultural or pastoral fields. PMID:24454700

Spatially random mortality in old-growth red pine forests of northern Minnesota

Treesearch

Tuomas ​Aakala; Shawn Fraver; Brian J. Palik; Anthony W. D' Amato

2012-01-01

Characterizing the spatial distribution of tree mortality is critical to understanding forest dynamics, but empirical studies on these patterns under old-growth conditions are rare. This rarity is due in part to low mortality rates in old-growth forests, the study of which necessitates long observation periods, and the confounding influence of tree in-growth during...

Sciurids in Pacific Northwest managed and old-growth forests.

Treesearch

A.B. Carey

1995-01-01

An understanding of the factors governing sciurid abundance in the Pacific Northwest is essential for prescribing forest management practices for second-growth forests where recovery of Spotted Owl (Strix occidentalis) populations and enhancement of biodiversity are objectives. We compared results of companion studies of sciurids in western...

Comparative physiology of a central hardwood old-growth forest canopy and forest gap

Treesearch

A. R. Gillespie; J. Waterman; K. Saylors

1993-01-01

Concerns of poor oak regeneration, changing climate, biodiversity patterns, and carbon cycling in the Central Hardwoods have prompted ecological and physiological studies of old-growth forests and their role in maintaining the landscape. To examine the effects of old-growth canopy structure on the physiological productivity of overstory and understory species, we...

Growth of Secondary Forest in Puerto Rico Between 1980 and 1985

Treesearch

P.L. Weaver; R.A. Birdsey

1990-01-01

Successive inventories in Puerto Rico provided the first estimates of secondary forest growth on a regional basis. The volume of growing stock trees increased by 32%, and timber volume by nearly 36%, on all classes of forest land between 1980 and 198.5. Timber volume growth rates (in m3ha-1yr-1 )...

Growth Decline Linked to Warming-Induced Water Limitation in Hemi-Boreal Forests

PubMed Central

Wu, Xiuchen; Liu, Hongyan; Guo, Dali; Anenkhonov, Oleg A.; Badmaeva, Natalya K.; Sandanov, Denis V.

2012-01-01

Hemi-boreal forests, which make up the transition from temperate deciduous forests to boreal forests in southern Siberia, have experienced significant warming without any accompanying increase in precipitation during the last 80 years. This climatic change could have a profound impact on tree growth and on the stability of forest ecosystems in this region, but at present evidence for these impacts is lacking. In this study, we report a recent dramatic decline in the growth of hemi-boreal forests, based on ring width measurements from three dominant tree-species (Pinus sylvestris, Larix sibirica and Larix gmelinii), sampled from eight sites in the region. We found that regional tree growth has become increasingly limited by low soil water content in the pre- and early-growing season (from October of the previous year to July of the current year) over the past 80 years. A warming-induced reduction in soil water content has also increased the climate sensitivity of these three tree species. Beginning in the mid-1980s, a clear decline in growth is evident for both the pine forests and the larch forests, although there are increasing trends in the proxy of soil water use efficiencies. Our findings are consistent with those from other parts of the world and provide valuable insights into the regional carbon cycle and vegetation dynamics, and should be useful for devising adaptive forest management strategies. PMID:22916142

Secondary forest regeneration benefits old-growth specialist bats in a fragmented tropical landscape.

PubMed

Rocha, Ricardo; Ovaskainen, Otso; López-Baucells, Adrià; Farneda, Fábio Z; Sampaio, Erica M; Bobrowiec, Paulo E D; Cabeza, Mar; Palmeirim, Jorge M; Meyer, Christoph F J

2018-02-28

Tropical forest loss and fragmentation are due to increase in coming decades. Understanding how matrix dynamics, especially secondary forest regrowth, can lessen fragmentation impacts is key to understanding species persistence in modified landscapes. Here, we use a whole-ecosystem fragmentation experiment to investigate how bat assemblages are influenced by the regeneration of the secondary forest matrix. We surveyed bats in continuous forest, forest fragments and secondary forest matrix habitats, ~15 and ~30 years after forest clearance, to investigate temporal changes in the occupancy and abundance of old-growth specialist and habitat generalist species. The regeneration of the second growth matrix had overall positive effects on the occupancy and abundance of specialists across all sampled habitats. Conversely, effects on generalist species were negligible for forest fragments and negative for secondary forest. Our results show that the conservation potential of secondary forests for reverting faunal declines in fragmented tropical landscapes increases with secondary forest age and that old-growth specialists, which are often of most conservation concern, are the greatest beneficiaries of secondary forest maturation. Our findings emphasize that the transposition of patterns of biodiversity persistence in island ecosystems to fragmented terrestrial settings can be hampered by the dynamic nature of human-dominated landscapes.

Structure and dynamics of an upland old-growth forest at Redwood National Park, California

Treesearch

Phillip J. van Mantgem; John D. Stuart

2012-01-01

Many current redwood forest management targets are based on old-growth conditions, so it is critical that we understand the variability and range of conditions that constitute these forests. Here we present information on the structure and dynamics from six one-hectare forest monitoring plots in an upland old-growth forest at Redwood National Park, California. We...

Mature and old-growth riparian forests: structure, dynamics, and effects on Adirondack stream habitats.

PubMed

Keeton, William S; Kraft, Clifford E; Warren, Dana R

2007-04-01

Riparian forests regulate linkages between terrestrial and aquatic ecosystems, yet relationships among riparian forest development, stand structure, and stream habitats are poorly understood in many temperate deciduous forest systems. Our research has (1) described structural attributes associated with old-growth riparian forests and (2) assessed linkages between these characteristics and in-stream habitat structure. The 19 study sites were located along predominantly first- and second-order streams in northern hardwood-conifer forests in the Adirondack Mountains of New York (U.S.A.). Sites were classified as mature forest (6 sites), mature with remnant old-growth trees (3 sites), and old-growth (10 sites). Forest-structure attributes were measured over stream channels and at varying distances from each bank. In-stream habitat features such as large woody debris (LWD), pools, and boulders were measured in each stream reach. Forest structure was examined in relation to stand age using multivariate techniques, ANOVA, and linear regression. We investigated linkages between forest structure and stream characteristics using similar methods, preceded by information-theoretic modeling (AIC). Old-growth riparian forest structure is more complex than that found in mature forests and exhibits significantly greater accumulations of aboveground tree biomass, both living and dead. In-stream LWD volumes were significantly (alpha = 0.05) greater at old-growth sites (200 m3/ha) compared to mature sites (34 m3/ha) and were strongly related to the basal area of adjacent forests. In-stream large-log densities correlated strongly with debris-dam densities. AIC models that included large-log density, debris-dam density, boulder density, and bankfull width had the most support for predicting pool density. There were higher proportions of LWD-formed pools relative to boulder-formed pools at old-growth sites as compared to mature sites. Old-growth riparian forests provide in

Winter Climate Limits Subantarctic Low Forest Growth and Establishment

PubMed Central

Harsch, Melanie A.; McGlone, Matt S.; Wilmshurst, Janet M.

2014-01-01

Campbell Island, an isolated island 600 km south of New Zealand mainland (52°S, 169°E) is oceanic (Conrad Index of Continentality  = −5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6°C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally. PMID:24691026

Spatial variability in forest growth—climate relationships in the Olympic Mountains, Washington.

Treesearch

Jill M. Nakawatase; David L. Peterson

2006-01-01

For many Pacific Northwest forests, little is known about the spatial and temporal variability in tree growth - climate relationships, yet it is this information that is needed to predict how forests will respond to future climatic change. We studied the effects of climatic variability on forest growth at 74 plots in the western and northeastern Olympic Mountains....

Involvement of allelopathy in inhibition of understory growth in red pine forests.

PubMed

Kato-Noguchi, Hisashi; Kimura, Fukiko; Ohno, Osamu; Suenaga, Kiyotake

2017-11-01

Japanese red pine (Pinus densiflora Sieb. et Zucc.) forests are characterized by sparse understory vegetation although sunlight intensity on the forest floor is sufficient for undergrowth. The possible involvement of pine allelopathy in the establishment of the sparse understory vegetation was investigated. The soil of the red pine forest floor had growth inhibitory activity on six test plant species including Lolium multiflorum, which was observed at the edge of the forest but not in the forest. Two growth inhibitory substances were isolated from the soil and characterized to be 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid. Those compounds are probably formed by degradation process of resin acids. Resin acids are produced by pine and delivered into the soil under the pine trees through balsam and defoliation. Threshold concentrations of 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid for the growth inhibition of L. multiflorum were 30 and 10μM, respectively. The concentrations of 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid in the soil were 312 and 397μM, respectively, which are sufficient concentrations to cause the growth inhibition because of the threshold. These results suggest that those compounds are able to work as allelopathic agents and may prevent from the invasion of herbaceous plants into the forests by inhibiting their growth. Therefore, allelopathy of red pine may be involved in the formation of the sparse understory vegetation. Copyright © 2017 Elsevier GmbH. All rights reserved.

Forests synchronize their growth in contrasting Eurasian regions in response to climate warming.

PubMed

Shestakova, Tatiana A; Gutiérrez, Emilia; Kirdyanov, Alexander V; Camarero, Jesús Julio; Génova, Mar; Knorre, Anastasia A; Linares, Juan Carlos; Resco de Dios, Víctor; Sánchez-Salguero, Raúl; Voltas, Jordi

2016-01-19

Forests play a key role in the carbon balance of terrestrial ecosystems. One of the main uncertainties in global change predictions lies in how the spatiotemporal dynamics of forest productivity will be affected by climate warming. Here we show an increasing influence of climate on the spatial variability of tree growth during the last 120 y, ultimately leading to unprecedented temporal coherence in ring-width records over wide geographical scales (spatial synchrony). Synchrony in growth patterns across cold-constrained (central Siberia) and drought-constrained (Spain) Eurasian conifer forests have peaked in the early 21st century at subcontinental scales (∼ 1,000 km). Such enhanced synchrony is similar to that observed in trees co-occurring within a stand. In boreal forests, the combined effects of recent warming and increasing intensity of climate extremes are enhancing synchrony through an earlier start of wood formation and a stronger impact of year-to-year fluctuations of growing-season temperatures on growth. In Mediterranean forests, the impact of warming on synchrony is related mainly to an advanced onset of growth and the strengthening of drought-induced growth limitations. Spatial patterns of enhanced synchrony represent early warning signals of climate change impacts on forest ecosystems at subcontinental scales.

Forests synchronize their growth in contrasting Eurasian regions in response to climate warming

PubMed Central

Shestakova, Tatiana A.; Gutiérrez, Emilia; Kirdyanov, Alexander V.; Camarero, Jesús Julio; Génova, Mar; Knorre, Anastasia A.; Linares, Juan Carlos; Sánchez-Salguero, Raúl; Voltas, Jordi

2016-01-01

Forests play a key role in the carbon balance of terrestrial ecosystems. One of the main uncertainties in global change predictions lies in how the spatiotemporal dynamics of forest productivity will be affected by climate warming. Here we show an increasing influence of climate on the spatial variability of tree growth during the last 120 y, ultimately leading to unprecedented temporal coherence in ring-width records over wide geographical scales (spatial synchrony). Synchrony in growth patterns across cold-constrained (central Siberia) and drought-constrained (Spain) Eurasian conifer forests have peaked in the early 21st century at subcontinental scales (∼1,000 km). Such enhanced synchrony is similar to that observed in trees co-occurring within a stand. In boreal forests, the combined effects of recent warming and increasing intensity of climate extremes are enhancing synchrony through an earlier start of wood formation and a stronger impact of year-to-year fluctuations of growing-season temperatures on growth. In Mediterranean forests, the impact of warming on synchrony is related mainly to an advanced onset of growth and the strengthening of drought-induced growth limitations. Spatial patterns of enhanced synchrony represent early warning signals of climate change impacts on forest ecosystems at subcontinental scales. PMID:26729860

Northwest Forest Plan—the first 10 years (1994-2003): status and trend of late-successional and old-growth forest.

Treesearch

Melinda Moeur; Thomas A. Spies; Miles Hemstrom; Jon R. Martin; James Alegria; Julie Browning; John Cissel; Warren B. Cohen; Thomas E. Demeo; Sean Healey; Ralph Warbington

2005-01-01

We monitored the status and trend of late-successional and old-growth forest (older forest) on 24 million ac of land managed by the Forest Service, Bureau of Land Management, and National Park Service in the Northwest Forest Plan (the Plan) area between 1994 and 2003. We developed baseline maps from satellite imagery of older forest conditions at the start of the Plan...

Forty-two years of change in an old-growth and second-growth beech-maple forest of north central Ohio

Treesearch

Natalie R. Pinheiro; P. Charles Goebel; David M. Hix

2008-01-01

Using data collected in 1964 and 2006, we examined changes in the composition and structure of a second-growth and old-growth beech-maple forest of Crall Woods, located in Ashland County of north central Ohio. Over the 42 years, the old-growth forest (estimated to be at least 250 years old) experienced a significant shift in species composition as American beech,...

Chapter 3: Old growth, disturbance, forest succession, and management in the area of the Northwest Forest Plan

Treesearch

Thomas A. Spies; Paul F. Hessburg; Carl N. Skinner; Klaus J. Puettmann; Matthew J. Reilly; Raymond J. Davis; Jane A. Kertis; Jonathan W. Long; David C. . Shaw

2018-01-01

In this chapter, we examine the scientific basis of the assumptions, management strategies, and goals of the Northwest Forest Plan (NWFP, or Plan) relative to the ecology of old-growth forests, forest successional dynamics, and disturbance processes. Our emphasis is on “coarse-filter” approaches to conservation (i.e., those that are concerned with entire ecosystems,...

Introduction to forest growth and yield

Treesearch

John W., Jr. Moser

1989-01-01

Forests are dynamic communities that are constantly changing. To the casual observer, only the most obvious change, such as the death of a tree, may be discernible. However, other changes are continually occurring. Trees grow in both height and diameter. This is termed survivor growth. Ingrowth occurs when a tree's diameter grows larger than an arbitrarily...

Status of growth and yield information for northern forest types

Treesearch

Dale S. Solomon

1977-01-01

Existing regional growth-and-yield information for most of the northern forest types is summarized by species. Present research is concentrated on growth-simulation models, constructed by either aggregating available information or through individual tree growth studies. A uniformity of more refined measurements is needed so that future growth models can be tried for...

Mapping forest structure, species gradients and growth in an urban area using lidar and hyperspectral imagery

NASA Astrophysics Data System (ADS)

Gu, Huan

Urban forests play an important role in the urban ecosystem by providing a range of ecosystem services. Characterization of forest structure, species variation and growth in urban forests is critical for understanding the status, function and process of urban ecosystems, and helping maximize the benefits of urban ecosystems through management. The development of methods and applications to quantify urban forests using remote sensing data has lagged the study of natural forests due to the heterogeneity and complexity of urban ecosystems. In this dissertation, I quantify and map forest structure, species gradients and forest growth in an urban area using discrete-return lidar, airborne imaging spectroscopy and thermal infrared data. Specific objectives are: (1) to demonstrate the utility of leaf-off lidar originally collected for topographic mapping to characterize and map forest structure and associated uncertainties, including aboveground biomass, basal area, diameter, height and crown size; (2) to map species gradients using forest structural variables estimated from lidar and foliar functional traits, vegetation indices derived from AVIRIS hyperspectral imagery in conjunction with field-measured species data; and (3) to identify factors related to relative growth rates in aboveground biomass in the urban forests, and assess forest growth patterns across areas with varying degree of human interactions. The findings from this dissertation are: (1) leaf-off lidar originally acquired for topographic mapping provides a robust, potentially low-cost approach to quantify spatial patterns of forest structure and carbon stock in urban areas; (2) foliar functional traits and vegetation indices from hyperspectral data capture gradients of species distributions in the heterogeneous urban landscape; (3) species gradients, stand structure, foliar functional traits and temperature are strongly related to forest growth in the urban forests; and (4) high uncertainties in our

Comparing models for growth and management of forest tracts

Treesearch

J.J. Colbert; Michael Schuckers; Desta Fekedulegn

2003-01-01

The Stand Damage Model (SDM) is a PC-based model that is easily installed, calibrated and initialized for use in exploring the future growth and management of forest stands or small wood lots. We compare the basic individual tree growth model incorporated in this model with alternative models that predict the basal area growth of trees. The SDM is a gap-type simulator...

An Old-Growth Definition for Red River Bottom Forests in the Eastern United States

Treesearch

Ted Shear; Mike Young; Robert Kellison

1997-01-01

Our goal was to develop a description of old-growth red river bottom forests of the Southeastern United States. We compared the characteristics of forests described in the scientific literature and forests we examined to various published criteria for old-growth condition. Because red rivers are a relatively new landscape feature (most 250 years old, resulting from...

Rapid warming accelerates tree growth decline in semi-arid forests of Inner Asia.

PubMed

Liu, Hongyan; Park Williams, A; Allen, Craig D; Guo, Dali; Wu, Xiuchen; Anenkhonov, Oleg A; Liang, Eryuan; Sandanov, Denis V; Yin, Yi; Qi, Zhaohuan; Badmaeva, Natalya K

2013-08-01

Forests around the world are subject to risk of high rates of tree growth decline and increased tree mortality from combinations of climate warming and drought, notably in semi-arid settings. Here, we assess how climate warming has affected tree growth in one of the world's most extensive zones of semi-arid forests, in Inner Asia, a region where lack of data limits our understanding of how climate change may impact forests. We show that pervasive tree growth declines since 1994 in Inner Asia have been confined to semi-arid forests, where growing season water stress has been rising due to warming-induced increases in atmospheric moisture demand. A causal link between increasing drought and declining growth at semi-arid sites is corroborated by correlation analyses comparing annual climate data to records of tree-ring widths. These ring-width records tend to be substantially more sensitive to drought variability at semi-arid sites than at semi-humid sites. Fire occurrence and insect/pathogen attacks have increased in tandem with the most recent (2007-2009) documented episode of tree mortality. If warming in Inner Asia continues, further increases in forest stress and tree mortality could be expected, potentially driving the eventual regional loss of current semi-arid forests. © 2013 John Wiley & Sons Ltd.

Basal area growth for 15 tropical trees species in Puerto Rico. Forest

Treesearch

B. R. Parresol

1995-01-01

The tabonuco forest of Puerto Rico support a diverse population of tree species valued for timber, fuel, food, wildlife food and cover, and erosion control among other use. tree basal area growth data spanning 39 years are avaible on 15 species from eigth permanent plots in Luquillo Experimental Forest. The complexity of the rain forest challeges current forest...

Benchmark carbon stocks from old-growth forests in northern New England, USA

Treesearch

Coeli M. Hoover; William B. Leak; Brian G. Keel

2012-01-01

Forests world-wide are recognized as important components of the global carbon cycle. Carbon sequestration has become a recognized forest management objective, but the full carbon storage potential of forests is not well understood. The premise of this study is that old-growth forests can be expected to provide a reasonable estimate of the upper limits of carbon...

An Old-Growth Definition for Evergreen Bay Forests and Related Seral Communities

Treesearch

Martha R. McKevlin

1996-01-01

This document describes old-growth conditions in an evergreen bay forest stand. Bay forests occur throughout the Atlantic and Gulf Coastal Plains. However, they are considered rare and are present across the landscape in a patchwork mosaic with other forest types in various stages of succession. Bay forests can be found associated with pocosins, Carolina bays and...

Old-growth Montane Longleaf Pine Forest Age Structure: A Preliminary Assessment

Treesearch

J. Morgan Varner; John S. Kush; Ralph S. Meldahl

1998-01-01

Presettlement longleaf pine forests of the Southeast have been described as uneven-aged forests comprised of even-aged patches. Less than 4000 ha of old-growth longleaf forest remains. From these few sites remaining, a limited volume of age related literature has evolved, and these studies have been limited to the Lower Coastal Plain physiographic province. This study...

Two decades of stability and change in old-growth forest at Mount Rainier National Park.

Treesearch

Steven A. Acker; Jerry F. Franklin; Sarah E. Greene; Ted B. Thomas; Robert Van Pelt; Kenneth J. Bible

2006-01-01

We examined how composition and structure of old-growth and mature forests at Mount Rainier National Park changed between the mid-1970s and mid-1990s. We assessed whether the patterns of forest dynamics observed in lower elevation old-growth forests in the Pacific Northwest held true for the higher-elevation forests of the Park. We used measurements of tree recruitment...

Phosphorus limits Eucalyptus grandis seedling growth in an unburnt rain forest soil

PubMed Central

Tng, David Y. P.; Janos, David P.; Jordan, Gregory J.; Weber, Ellen; Bowman, David M. J. S.

2014-01-01

Although rain forest is characterized as pyrophobic, pyrophilic giant eucalypts grow as rain forest emergents in both temperate and tropical Australia. In temperate Australia, such eucalypts depend on extensive, infrequent fires to produce conditions suitable for seedling growth. Little is known, however, about constraints on seedlings of tropical giant eucalypts. We tested whether seedlings of Eucalyptus grandis experience edaphic constraints similar to their temperate counterparts. We hypothesized that phosphorous addition would alleviate edaphic constraints. We grew seedlings in a factorial experiment combining fumigation (to simulate nutrient release and soil pasteurization by fire), soil type (E. grandis forest versus rain forest soil) and phosphorus addition as factors. We found that phosphorus was the principal factor limiting E. grandis seedling survival and growth in rain forest soil, and that fumigation enhanced survival of seedlings in both E. grandis forest and rain forest soil. We conclude that similar to edaphic constraints on temperate giant eucalypts, mineral nutrient and biotic attributes of a tropical rain forest soil may hamper E. grandis seedling establishment. In rain forest soil, E. grandis seedlings benefited from conditions akin to a fire-generated ashbed (i.e., an “ashbed effect”). PMID:25339968

Structure and development of old-growth, unmanaged second-growth, and extended rotation Pinus resinosa forests in Minnesota, USA

Treesearch

Emily J. Silver; Anthony W. D' Amato; Shawn Fraver; Brian J. Palik; John B. Bradford

2013-01-01

The structure and developmental dynamics of old-growth forests often serve as important baselines for restoration prescriptions aimed at promoting more complex structural conditions in managed forest landscapes. Nonetheless, long-term information on natural patterns of development is rare for many commercially important and ecologically widespread forest types....

Georgia's forests, 1989

Treesearch

Raymond M. Sheffield; Tony G. Johnson

1993-01-01

This resource bulletin presents the principal findings of the sixth inventory of Georgia's forest resources. Data on the extent, condition, and classification of forest land and associated timber volumes, growth, removals, and mortality are described and interpreted. Whereas data on nontimber commodities associated with forests were also collected, evaluations of...

Differences in Townsend's chipmunk populations between second- and old-growth forests in western Oregon

Treesearch

D.K. Rosenberg; R.G. Anthony

1993-01-01

Because Townsend's chipmunks (Tomias townsendii) may be important in maintaining natural ecosystem processes in forests in the central Oregon Cascade Range, we compared their population characteristics in young second-growth and old-growth forests. We live-trapped Townsend's chipmunks in 5 young (30-60 yr old) second-growth and 5 old-...

Old-growth forests in the Sierra Nevada: by type in 1945 and 1993 and ownership in 1993.

Treesearch

Debby Beardsley; Charles Bolsinger; Ralph. Warbington

1999-01-01

This report presents estimates of old-growth forest area in the Sierra Nevada by forest type in 1993 and 1945 and by old-growth stand characteristics as they existed in 1993. Ecological old-growth definitions for each forest type are used.

Forest stand structure and pattern of old-growth western hemlock/Douglas-fir and mixed-conifer forests

Treesearch

Malcolm North; Jiquan Chen; Brian Oakley; Bo Song; Mark Rudnicki; Andrew Gray; Jim Innes

2004-01-01

With fire suppression, many western forests are expected to have fewer gaps and higher stem density of shade-tolerant species as light competition becomes a more significant influence on stand pattern and composition. We compared species composition, structure, spatial pattern, and environmental factors such as light and soil moisture between two old-growth forests:...

Carbon storage in mountainous headwater streams: The role of old-growth forest and logjams

NASA Astrophysics Data System (ADS)

Beckman, Natalie D.; Wohl, Ellen

2014-03-01

We measured wood piece characteristics and particulate organic matter (POM) in stored sediments in 30 channel-spanning logjams along headwater streams in the Colorado Front Range, USA. Logjams are on streams flowing through old-growth (>200 years), disturbed (<200 years, natural disturbance), or altered (<200 years, logged) subalpine conifer forest. We examined how channel-spanning logjams influence riverine carbon storage (measured as the total volatile carbon fraction of stored sediment and instream wood). Details of carbon storage associated with logjams reflect age and disturbance history of the adjacent riparian forest. A majority of the carbon within jams is stored as wood. Wood volume is significantly larger in old-growth and disturbed reaches than in altered reaches. Carbon storage also differs in relation to forest characteristics. Sediment from old-growth streams has significantly higher carbon content than altered streams. Volume of carbon stored in jam sediment correlates with jam wood volume in old-growth and disturbed forests, but not in altered forests. Forest stand age and wood volume within a jam explain 43% of the variation of carbon stored in jam sediment. First-order estimates of the amount of carbon stored within a stream reach show an order of magnitude difference between disturbed and altered reaches. Our first-order estimates of reach-scale riverine carbon storage suggest that the carbon per hectare stored in streams is on the same order of magnitude as the carbon stored as dead biomass in terrestrial subalpine forests of the region. Of particular importance, old-growth forest correlates with more carbon storage in rivers.

Ecological setting of the Wind River old-growth forest.

Treesearch

David C. Shaw; Jerry F. Franklin; Ken Bible; Jeffrey Klopatek; Elizabeth Freeman; Sarah Greene; Geoffrey G. Parker

2004-01-01

The Wind River old-growth forest, in the southern Cascade Range of Washington State, is a cool (average annual temperature, 8.7°C), moist (average annual precipitation, 2223 mm), 500-year-old Douglas-fir-western hemlock forest of moderate to low productivity at 371-m elevation on a less than 10% slope. There is a seasonal snowpack (November-March), and rain-on-snow and...

Spatial and Temporal Relationships of Old-Growth and Secondary Forests in Indiana, USA

Treesearch

Martin A. Spetich; George R. Parker; Eric J. Gustafson

1997-01-01

We examined the spatial pattern of forests in Indiana to: (1) determine the extent, connectivity and percent edge of all forests, (2) examine the change in connectivity among these forests if all riparian zones were replanted to forest or other native vegetation, (3) determine the location, spatial dispersion and percent edge of current old-growth forest remnants, (4)...

The effect of size and competition on tree growth rate in old-growth coniferous forests

USGS Publications Warehouse

Das, Adrian

2012-01-01

Tree growth and competition play central roles in forest dynamics. Yet models of competition often neglect important variation in species-specific responses. Furthermore, functions used to model changes in growth rate with size do not always allow for potential complexity. Using a large data set from old-growth forests in California, models were parameterized relating growth rate to tree size and competition for four common species. Several functions relating growth rate to size were tested. Competition models included parameters for tree size, competitor size, and competitor distance. Competitive strength was allowed to vary by species. The best ranked models (using Akaike’s information criterion) explained between 18% and 40% of the variance in growth rate, with each species showing a strong response to competition. Models indicated that relationships between competition and growth varied substantially among species. The results also suggested that the relationship between growth rate and tree size can be complex and that how we model it can affect not only our ability to detect that complexity but also whether we obtain misleading results. In this case, for three of four species, the best model captured an apparent and unexpected decline in potential growth rate for the smallest trees in the data set.

Chemical vapour deposition growth of carbon nanotube forests: kinetics, morphology, composition, and their mechanisms

NASA Astrophysics Data System (ADS)

Vinten, Phillip

This thesis analyzes the chemical vapour deposition (CVD) growth of vertically aligned carbon nanotube (CNT) forests in order to understand how CNT forests grow, why they stop growing, and how to control the properties of the synthesized CNTs. in situ kinetics data of the growth of CNT forests are gathered by in situ optical microscopy. The overall morphology of the forests and the characteristics of the individual CNTs in the forests are investigated using scanning electron microscopy and Raman spectroscopy. The in situ data show that forest growth and termination are activated processes (with activation energies on the order of 1 eV), suggesting a possible chemical origin. The activation energy changes at a critical temperature for ethanol CVD (approximately 870°C). These activation energies and critical temperature are also seen in the temperature dependence of several important characteristics of the CNTs, including the defect density as determined by Raman spectroscopy. This observation is seen across several CVD processes and suggests a mechanism of defect healing. The CNT diameter also depends on the growth temperature. In this thesis, a thermodynamic model is proposed. This model predicts a temperature and pressure dependence of the CNT diameter from the thermodynamics of the synthesis reaction and the effect of strain on the enthalpy of formation of CNTs. The forest morphology suggests significant interaction between the constituent CNTs. These interactions may play a role in termination. The morphology, in particular a microscale rippling feature that is capable of diffracting light, suggest a non-uniform growth rate across the forest. A gas phase diffusion model predicts a non-uniform distribution of the source gas. This gas phase diffusion is suggested as a possible explanation for the non-uniform growth rate. The gas phase diffusion is important because growth by acetylene CVD is found to be very efficient (approximately 30% of the acetylene is

A diameter growth model for single-stem growth forms for the interior west forest inventory and analysis’s region

Treesearch

Michael T. Thompson

2015-01-01

The Interior West Forest Inventory and Analysis Unit (IWFIA) will soon transition from a regional system to a national FIA system for compiling estimates of forest growth, removals, and mortality. The national system requires regional diameter-growth models to estimate diameters on trees in situations where the initial or terminal diameter is not known at the beginning...

Analysis of growth trend changes for 51 temperate tree species using Korea national forest inventory data

NASA Astrophysics Data System (ADS)

Park, M.; Moon, M.; Park, J.; Cho, S.; Kim, H. S.

2016-12-01

Individual tree growth rates can be affected by various factors such as species, soil fertility, stand development stage, disturbance, and climate etc. To estimate the effect of changes in tree growth rate on the structure and functionality of forest ecosystem in the future, we analyzed the change of species-specific growth trends using the fifth Korea national forest inventory data, which was collected from 2006 to 2010. The ring samples of average tree were collected from nationwide inventory plots and the total number of individual tree ring series was 69,128 covering 185 tree species. Among those, fifty one species with more than 100 tree ring series were used for our analysis. For growth-trend analysis, standardized regional curves of individual species growth were generated from three forest zone in South Korea; subarctic, cool temperate, warm temperate forest zone. Then individual tree ring series was indexed by dividing the growth of the tree by expected growth from standardized regional curves. Then the ratio of all tree ring series were aligned by year and the Spearman's correlation coefficient of each species was calculated. The results show that most of species had increasing growth rates as forests developed after Korean war. For the last thirty years, 67.3% of species including Quercus spp. and Zelkova serrata had positive growth trends, on the other hand, 11.5% of species including Pinus spp. showed negative growth trends probably due to the changes in successional stages in Korean forests and climate change. These trends also vary with climate zone and species. For examples, Pinus densiflora, which showed negative growth trend overall, had steep negative growth trends in boreal and temperate zone, whereas it showed no specific trend in sub-tropical climate zone. Our trend analysis on 51 temperate tree species growth will be essential to predict the temperate forests species change for the this century.

Long-term growth trends and time series of elemental wood composition from two old-growth forests - natural versus anthropogenic influences

NASA Astrophysics Data System (ADS)

Scharnweber, Tobias; van der Maaten, Ernst; Heinrich, Ingo; Buras, Allan; van der Maaten Theunissen, Marieke; Wilmking, Martin

2014-05-01

In contrast to extreme environments with low human impact, where often one specific (climatic) factor is limiting tree growth, dendrochronological research in the temperate zone has to cope with a wide variety of climatic and non-climatic drivers. Sophisticated statistical tools, like various detrending and filtering techniques, allow for a rather precise analysis of high-frequency (annual) climate-growth relationships. However, as almost all forests in the temperate zone are to some degree influenced by human activities, it is difficult to separate anthropogenic from climatic influence on the lower time-frequencies of decades to centuries. Footprints of human activity in time series of tree-ring parameters might be caused directly through forest utilization (logging) or indirectly through environmental changes such as eutrophication or atmospheric pollution. The former can be elucidated by traditional dendrochronological techniques based on ring parameters; evaluation of the latter requires additional proxies such as dendrochemical data. For the interpretation of long-term trends and the calibration of tree-ring based reconstructions it is therefore necessary to study tree growth in as undisturbed forest environments as possible. Comparison with dendrochronological time series from managed forest might then allow separation of climatic- from anthropogenic signals. Here, we present long-term growth trends for the broadleaved tree species common beech, pedunculate oak and sycamore maple, from two protected old-growth forests in northern Germany (one with a documented last logging activity dating back to 1527), and compare those with well-replicated regional chronologies from other, mostly managed forests. Our results indicate that several low frequency trends that can be found in many regional chronologies are likely caused by synchronous periods of heavy loggings as for example during the years following World War II, and do not relate to climatic drivers. In

Information about old growth for selected forest type groups in the eastern United States.

Treesearch

Lucy E. Tyrrell; Gregory J. Nowacki; David S. Buckley; Elizabeth A. Nauertz; Jeffrey N. Niese; Jeanette L. Rollinger; John C. Zasada; John C. Zasada

1998-01-01

Compiles information about old-growth attributes for nine forest type groups that occur in the eastern United States. A range of values for each old-growth attribute for each forest type is summarized regionally from published and unpublished sources.

Assessing the effects of management on forest growth across France: insights from a new functional-structural model.

PubMed

Guillemot, Joannès; Delpierre, Nicolas; Vallet, Patrick; François, Christophe; Martin-StPaul, Nicolas K; Soudani, Kamel; Nicolas, Manuel; Badeau, Vincent; Dufrêne, Eric

2014-09-01

The structure of a forest stand, i.e. the distribution of tree size features, has strong effects on its functioning. The management of the structure is therefore an important tool in mitigating the impact of predicted changes in climate on forests, especially with respect to drought. Here, a new functional-structural model is presented and is used to assess the effects of management on forest functioning at a national scale. The stand process-based model (PBM) CASTANEA was coupled to a stand structure module (SSM) based on empirical tree-to-tree competition rules. The calibration of the SSM was based on a thorough analysis of intersite and interannual variability of competition asymmetry. The coupled CASTANEA-SSM model was evaluated across France using forest inventory data, and used to compare the effect of contrasted silvicultural practices on simulated stand carbon fluxes and growth. The asymmetry of competition varied consistently with stand productivity at both spatial and temporal scales. The modelling of the competition rules enabled efficient prediction of changes in stand structure within the CASTANEA PBM. The coupled model predicted an increase in net primary productivity (NPP) with management intensity, resulting in higher growth. This positive effect of management was found to vary at a national scale across France: the highest increases in NPP were attained in forests facing moderate to high water stress; however, the absolute effect of management on simulated stand growth remained moderate to low because stand thinning involved changes in carbon allocation at the tree scale. This modelling approach helps to identify the areas where management efforts should be concentrated in order to mitigate near-future drought impact on national forest productivity. Around a quarter of the French temperate oak and beech forests are currently in zones of high vulnerability, where management could thus mitigate the influence of climate change on forest yield.

South Carolina's forests

Treesearch

John B. Tansey; Cecil C. Hutchins

1988-01-01

This report presents the principal findings of the sixth evaluation of South Carolina's forest resources. Data concerning the extent and condition of forest land, associated timber volumes, and rates of growth and removals are included. In accordance with the Forest and Rangeland Renewable Resources Planning Act (RPA) of 1974, the sixth inventory of South Carolina...

Northwest Forest Plan–the first 15 years (1994–2008): status and trends of late-successional and old-growth forests

Treesearch

Melinda Moeur; Janet L. Ohmann; Robert E. Kennedy; Warren B. Cohen; Matthew J. Gregory; Zhiqiang Yang; Heather M. Roberts; Thomas A. Spies; Maria Fiorella

2011-01-01

Late-successional and old-growth (LSOG) monitoring characterizes the status and trends of older forests to answer such questions as: How much older forest is there? Where is it? How much has changed and from what causes? Is the Northwest Forest Plan (the Plan) maintaining or restoring older forest ecosystems to desired conditions on federal lands in the Plan area? This...

Increased water deficit decreases Douglas fir growth throughout western US forests.

PubMed

Restaino, Christina M; Peterson, David L; Littell, Jeremy

2016-08-23

Changes in tree growth rates can affect tree mortality and forest feedbacks to the global carbon cycle. As air temperature increases, evaporative demand also increases, increasing effective drought in forest ecosystems. Using a spatially comprehensive network of Douglas fir (Pseudotsuga menziesii) chronologies from 122 locations that represent distinct climate environments in the western United States, we show that increased temperature decreases growth via vapor pressure deficit (VPD) across all latitudes. Using an ensemble of global circulation models, we project an increase in both the mean VPD associated with the lowest growth extremes and the probability of exceeding these VPD values. As temperature continues to increase in future decades, we can expect deficit-related stress to increase and consequently Douglas fir growth to decrease throughout its US range.

Increased water deficit decreases Douglas fir growth throughout western US forests

USGS Publications Warehouse

Restaino, Christina M; Peterson, David L.; Littell, Jeremy

2016-01-01

Changes in tree growth rates can affect tree mortality and forest feedbacks to the global carbon cycle. As air temperature increases, evaporative demand also increases, increasing effective drought in forest ecosystems. Using a spatially comprehensive network of Douglas-fir (Pseudotsuga menziesii) chronologies from 122 locations that experience distinctly different climate in the western United States, we show that increased temperature decreases growth via vapor pressure deficit (VPD) across all latitudes. Under an ensemble of global circulation models, we project an increase in both the mean VPD associated with the lowest growth extremes and the probability of exceeding these VPD values. As temperature continues to increase in future decades, we can expect deficit-related stress to increase and consequently Douglas-fir growth to decrease throughout its US range.

Who is the new sheriff in town regulating boreal forest growth?

NASA Astrophysics Data System (ADS)

Park Williams, A.; Xu, Chonggang; McDowell, Nate G.

2011-12-01

Climate change appears to be altering boreal forests. One recently observed symptom of these changes has been an apparent weakening of the positive relationship between high-latitude boreal tree growth and temperature at some sites (D'Arrigo et al 2008). This phenomenon is referred to as the 'divergence problem' or 'divergence effect' and is thought to reflect a non-linear relationship between temperature and tree growth, where recent warming has allowed other factors besides growing-season temperature to emerge as dominant regulators of annual growth rates. Figure 1 demonstrates this divergence phenomenon with records of tree-ring widths collected from 59 populations of white spruce in Alaska 1. Key tendencies among these populations include: (1) growth is most sensitive to temperature during relatively cold growing seasons (figure 1(a)), (2) populations at colder sites are more sensitive to temperature than those at warmer sites are (figure 1(a)), and (3) growth at warmer sites may respond negatively to increased temperature beyond some optimal growing-season temperature (figure 1(b)). Since temperature is rising rapidly at high latitudes, one interpretation of figures 1(a) and (b) is that warming has promoted increased growth at colder sites, but caused growth to plateau or slow at warmer sites. Corroborating this interpretation, satellite imagery and tree-ring data indicate increasing vegetation productivity near the forest-tundra boundary but declining productivity in warmer regions within forest interiors (e.g., Bunn and Goetz 2006, Beck and Goetz 2011, Beck et al 2011, Berner et al 2011). Will continued warming cause a northward migration of boreal forests, with mortality in the warmer, southern locations and expansion into the colder tundra? This question is difficult to answer because many factors besides temperature influence boreal forest dynamics. Widespread productivity declines within interior boreal forests appear to be related to warming

Analyzing growth and mortality in a subtropical urban forest ecosystem

Treesearch

Alicia B. Lawrence; Fancisco J. Escobedo; Christina L. Staudhammera; Wayne Zipperer Zipperer

2012-01-01

Information on urban tree growth, mortality and in-growth is currently being used to estimate urban forest structure changes and ecosystem services such as carbon sequestration. This study reports on tree diameter growth and mortality in 65 plots distributed among four land use categories, which were established in 2005/2006 in Gainesville, Florida, USA and were re-...

Carbon changes in conterminous US forests associated with growth and major disturbances: 1992-2001

Treesearch

Daolan Zheng; Linda S. Heath; Mark J. Ducey; James E. Smith

2011-01-01

We estimated forest area and carbon changes in the conterminous United States using a remote sensing based land cover change map, forest fire data from the Monitoring Trends in Burn Severity program, and forest growth and harvest data from the USDA Forest Service, Forest Inventory and Analysis Program. Natural and human-associated disturbances reduced the forest...

Seventy years of forest growth and community dynamics in an undisturbed northern hardwood forest

Treesearch

Jennifer Pontius; Joshua M. Halman; Paul G. Schaberg

2016-01-01

Long-term forest inventories provide a unique opportunity to quantify changes in forest structure and evaluate how changes compare with current stand development models. An examination of a 70 year record at the Bartlett Experimental Forest, New Hampshire, indicated that although species abundances have primarily changed as expected under natural succession, some...

Regional distribution and dynamics of coarse woody debris in Midwestern old-growth forests

Treesearch

Martin A. Spetich; Stephen R. Shifley; George R. Parker

1999-01-01

Old-growth forests have been noted for containing significant quantities of deadwood. However, there has been no coordinated effort to quantify the deadwood component of old-growth remnants across large regions of temperate deciduous forest. We present results of a regional inventory that quantifies and examines regional and temporal trends for deadwood in upland old-...

Basal area growth impacts of dwarf misletoe on western hemlock in an old-growth forest

Treesearch

David C. Shaw; Huso Manuela; Howard Bruner

2008-01-01

We investigated the effect of western hemlock dwarf mistletoe (Arceuthobium tsugense (Rosend.) G.N. Jones ssp. tsugense) on the 13-year basal area growth of large (>45.7 cm diameter at breast height) western hemlock (Tsuga heterophylla (Raf.) Sarg.) trees in an old-growth forest in southwestern Washington...

Characteristics of remnant old-growth forests in the northern Coast Range of Oregon and comparison to surrounding landscapes.

Treesearch

Andrew N. Gray; Vicente J. Monleon; Thomas A. Spies

2009-01-01

Old-growth forests provide unique habitat features and landscape functions compared to younger stands. The goals of many forest management plans in the Pacific Northwest include increasing the area of late-successional and old-growth forests. The goal of this study was to describe existing old-growth forests in the northern Oregon Coast Range that might serve as...

A Long-Term View of Old-Growth Deciduous Forests

Treesearch

James T. Tanner; Paul B. Hamel

2001-01-01

Lowland old-growth forests in the Southeastern United States and Eastern Europe (Poland) survived because of accidents of history, topography, and ownership until they came under governmental protection. Such old-growth stands are the similar the world over; they have trees of many ages, patchy distribution of habitats, and a variety of microhabitats, all of which...

Defining old growth for fire-adapted forests of the Western United States

Treesearch

Merrill R. Kaufmann; Daniel Binkley; Peter Z. Fule; Johnson Marlin; Scott L. Stephens; Thomas W. Swetnam

2007-01-01

There are varying definitions of old-growth forests because of differences in environment and differing fire influence across the Intermountain West. Two general types of forests reflect the role of fire: 1) forests shaped by natural changes in structure and species makeup-plant succession-that are driven by competitive differences among species and individual trees...

The linkages between photosynthesis, productivity, growth and biomass in lowland Amazonian forests.

PubMed

Malhi, Yadvinder; Doughty, Christopher E; Goldsmith, Gregory R; Metcalfe, Daniel B; Girardin, Cécile A J; Marthews, Toby R; Del Aguila-Pasquel, Jhon; Aragão, Luiz E O C; Araujo-Murakami, Alejandro; Brando, Paulo; da Costa, Antonio C L; Silva-Espejo, Javier E; Farfán Amézquita, Filio; Galbraith, David R; Quesada, Carlos A; Rocha, Wanderley; Salinas-Revilla, Norma; Silvério, Divino; Meir, Patrick; Phillips, Oliver L

2015-06-01

Understanding the relationship between photosynthesis, net primary productivity and growth in forest ecosystems is key to understanding how these ecosystems will respond to global anthropogenic change, yet the linkages among these components are rarely explored in detail. We provide the first comprehensive description of the productivity, respiration and carbon allocation of contrasting lowland Amazonian forests spanning gradients in seasonal water deficit and soil fertility. Using the largest data set assembled to date, ten sites in three countries all studied with a standardized methodology, we find that (i) gross primary productivity (GPP) has a simple relationship with seasonal water deficit, but that (ii) site-to-site variations in GPP have little power in explaining site-to-site spatial variations in net primary productivity (NPP) or growth because of concomitant changes in carbon use efficiency (CUE), and conversely, the woody growth rate of a tropical forest is a very poor proxy for its productivity. Moreover, (iii) spatial patterns of biomass are much more driven by patterns of residence times (i.e. tree mortality rates) than by spatial variation in productivity or tree growth. Current theory and models of tropical forest carbon cycling under projected scenarios of global atmospheric change can benefit from advancing beyond a focus on GPP. By improving our understanding of poorly understood processes such as CUE, NPP allocation and biomass turnover times, we can provide more complete and mechanistic approaches to linking climate and tropical forest carbon cycling. © 2015 John Wiley & Sons Ltd.

Growth response in Allegheny hardwood forests after diameter-limit pulpwood cuttings

Treesearch

A. F. Hough

1954-01-01

Valuable second-growth Allegheny hardwood-hemlock forests are found in the High Plateau section of the northern Allegheny Plateau. These forests are valuable as a habitat for wildlife, for regulating streamflow and protecting against erosion, for recreation, and as a source of timber products for industry.

Northwest Forest Plan–the first 20 years (1994-2013): status and trends of late-successional and old-growth forests

Treesearch

Raymond J. Davis; Janet L. Ohmann; Robert E. Kennedy; Warren B. Cohen; Matthew J. Gregory; Zhiqiang Yang; Heather M. Roberts; Andrew N. Gray; Thomas A. Spies

2015-01-01

This is the third in a series of periodic monitoring reports on LSOG or latesuccessional and old-growth (older) forest status trends on federally administered lands since implementation of the Northwest Forest Plan (NWFP or the Plan) in 1994. The objective of this monitoring is to determine if the NWFP is providing for conservation and management of older forests as...

The growth-defense trade-off and habitat specialization by plants in Amazonian forests.

PubMed

Fine, Paul V A; Miller, Zachariah J; Mesones, Italo; Irazuzta, Sebastian; Appel, Heidi M; Stevens, M Henry H; Sääksjärvi, Ilari; Schultz, Jack C; Coley, Phyllis D

2006-07-01

Tropical forests include a diversity of habitats, which has led to specialization in plants. Near Iquitos, in the Peruvian Amazon, nutrient-rich clay forests surround nutrient-poor white-sand forests, each harboring a unique composition of habitat specialist trees. We tested the hypothesis that the combination of impoverished soils and herbivory creates strong natural selection for plant defenses in white-sand forest, while rapid growth is favored in clay forests. Recently, we reported evidence from a reciprocal-transplant experiment that manipulated the presence of herbivores and involved 20 species from six genera, including phylogenetically independent pairs of closely related white-sand and clay specialists. When protected from herbivores, clay specialists exhibited faster growth rates than white-sand specialists in both habitats. But, when unprotected, white-sand specialists outperformed clay specialists in white-sand habitat, and clay specialists outperformed white-sand specialists in clay habitat. Here we test further the hypothesis that the growth defense trade-off contributes to habitat specialization by comparing patterns of growth, herbivory, and defensive traits in these same six genera of white-sand and clay specialists. While the probability of herbivore attack did not differ between the two habitats, an artificial defoliation experiment showed that the impact of herbivory on plant mortality was significantly greater in white-sand forests. We quantified the amount of terpenes, phenolics, leaf toughness, and available foliar protein for the plants in the experiment. Different genera invested in different defensive strategies, and we found strong evidence for phylogenetic constraint in defense type. Overall, however, we found significantly higher total defense investment for white-sand specialists, relative to their clay specialist congeners. Furthermore, herbivore resistance consistently exhibited a significant trade-off against growth rate in each of

Increased water deficit decreases Douglas fir growth throughout western US forests

PubMed Central

Restaino, Christina M.; Peterson, David L.; Littell, Jeremy

2016-01-01

Changes in tree growth rates can affect tree mortality and forest feedbacks to the global carbon cycle. As air temperature increases, evaporative demand also increases, increasing effective drought in forest ecosystems. Using a spatially comprehensive network of Douglas fir (Pseudotsuga menziesii) chronologies from 122 locations that represent distinct climate environments in the western United States, we show that increased temperature decreases growth via vapor pressure deficit (VPD) across all latitudes. Using an ensemble of global circulation models, we project an increase in both the mean VPD associated with the lowest growth extremes and the probability of exceeding these VPD values. As temperature continues to increase in future decades, we can expect deficit-related stress to increase and consequently Douglas fir growth to decrease throughout its US range. PMID:27503880

Structure and dynamics of an upland old- growth forest at Redwood National Park, California

USGS Publications Warehouse

van Mantgem, Philip J.; Stuart, John D.

2011-01-01

Many current redwood forest management targets are based on old-growth conditions, so it is critical that we understand the variability and range of conditions that constitute these forests. Here we present information on the structure and dynamics from six one-hectare forest monitoring plots in an upland old-growth forest at Redwood National Park, California. We surveyed all stems =20 cm DBH in 1995 and 2010, allowing us to estimate any systematic changes in these stands. Stem size distributions for all species and for redwood (Sequoia sempervirens (D. Don) Endl.) alone did not appreciably change over the 15 year observation interval. Recruitment and mortality rates were roughly balanced, as were basal area dynamics (gains from recruitment and growth versus losses from mortality). Similar patterns were found for Sequoia alone. The spatial structure of stems at the plots suggested a random distribution of trees, though the pattern for Sequoia alone was found to be significantly clumped at small scales (< 5 m) at three of the six plots. These results suggest that these forests, including populations of Sequoia, have been generally stable over the past 15 years at this site, though it is possible that fire exclusion may be affecting recruitment of smaller Sequoia (< 20 cm DBH). The non-uniform spatial arrangement of stems also suggests that restoration prescriptions for second-growth redwood forests that encourage uniform spatial arrangements do not appear to mimic current upland old-growth conditions.

Regional Rates of Young US Forest Growth Estimated From Annual Landsat Disturbance History and IKONOS Stereo Imagery

NASA Technical Reports Server (NTRS)

Neigh, Christopher S. R.; Masek, Jeffrey G.; Bourget, Paul; Rishmawi, Khaldoun; Zhao, Feng; Huang, Chengquan; Cook, Bruce D.; Nelson, Ross

2015-01-01

Forests of the Contiguous United States (CONUS) have been found to be a large contributor to the global atmospheric carbon sink. The magnitude and nature of this sink is still uncertain and recent studies have sought to define the dynamics that control its strength and longevity. The Landsat series of satellites has been a vital resource to understand the long-term changes in land cover that can impact ecosystem function and terrestrial carbonstock. We combine annual Landsat forest disturbance history from 1985 to 2011 with single date IKONOS stereoimagery to estimate the change in young forest canopy height and above ground live dry biomass accumulation for selected sites in the CONUS. Our approach follows an approximately linear growth rate following clearing over short intervals and does not estimate the distinct non-linear growth rate over longer intervals.We produced canopy height models by differencing digital surface models estimated from IKONOS stereo pairs with national elevation data (NED). Correlations between height and biomass were established independently using airborne LiDAR, and then applied to the IKONOS-estimated canopy height models. Graphing current biomass against time since disturbance provided biomass accumulation rates. For 20 study sites distributed across five regions of the CONUS, 19 showed statistically significant recovery trends (p is less than 0.001) with canopy growth from 0.26 m yr-1to 0.73 m yr-1. Above ground live dry biomass (AGB) density accumulation ranged from 1.31 t/ha yr-1 to 12.47 t/ha yr-1. Mean forest AGB accumulationwas 6.31 t/ha yr-1 among all sites with significant growth trends. We evaluated the accuracy of our estimates by comparing to field estimated site index curves of growth, airborne LiDAR data, and independent model predictions of C accumulation. Growth estimates found with this approach are consistent with site index curves and total biomass estimates fall within the range of field estimates. This is aviable

Nutrient status and plant growth effects of forest soils in the Basin of Mexico

Treesearch

Mark E. Fenn; V.M. Perea-Estrada; L.I. de Bauer; M. Pérez-Suárez; D.R. Parker; V.M. Cetina-Alcalá

2006-01-01

The nutrient status of forest soils in the Mexico City Air Basin was evaluated by observing plant growth responses to fertilization with N, P or both nutrients combined. P deficiency was the most frequent condition for soil from two high pollution sites and N deficiency was greatest at a low N deposition site. Concentrations of Pb and Ni, and to a lesser extent Zn and...

Increased water deficit decreases Douglas fir growth throughout western US forests

Treesearch

Christina M. Restaino; David L. Peterson; Jeremy Littell

2016-01-01

Changes in tree growth rates can affect tree mortality and forest feedbacks to the global carbon cycle. As air temperature increases, evaporative demand also increases, increasing effective drought in forest ecosystems. Using a spatially comprehensive network of Douglas fir (Pseudotsuga menziesii) chronologies from 122 locations that represent distinct climate...

Old-growth forests in the Southwest and Rocky Mountain Regions - Proceedings of a workshop

Treesearch

Merrill R. Kaufman; W. H. Moir; Richard L. Bassett

1992-01-01

This paper reviews the science and management of old-growth forests and summarizes discussions among 30 participants at a workshop in Portal, Arizona, March 9-13, 1992. Concepts of old-growth forests - the perceptions, values, definitions, characteristic features, ecological functions, and landscape importance - vary widely. Because concepts are complex,...

Forest carbon dynamics associated with growth and disturbances in Oklahoma and Texas, 1992-2006

Treesearch

Daolan Zheng; Linda S. Heath; Mark J. Ducey; James E. Smith

2013-01-01

Quantifying forest carbon changes associated with growth and major disturbances is important for management of greenhouse gas emissions related to forests. Regional-level approaches with improved local growth data may refine estimates obtained using coarser resolution information. This study integrates remote-sensing-derived land cover change products, harvest data,...

Production, respiration, and overall carbon balance in an old-growth Pseudotsuga-Tsuga forest ecosystem

Treesearch

Mark E. Harmon; Ken Bible; Michael G. Ryan; David C. Shaw; H. Chen; Jeffrey Klopatek; Xia Li

2004-01-01

Ground-based measurements of stores, growth, mortality, litterfall, respiration, and decomposition were conducted in an old-growth forest at Wind River Experimental Forest, Washington. These measurements were used to estimate: Gross (GPP) and Net Primary Production (NPP); autotrophic (Ra) and heterotrophic (Rh) respiration; and Net Ecosystem Production (NEP). Monte...

Revaluing unmanaged forests for climate change mitigation.

PubMed

Krug, Joachim; Koehl, Michael; Kownatzki, Dierk

2012-11-14

Unmanaged or old-growth forests are of paramount importance for carbon sequestration and thus for the mitigation of climate change among further implications, e.g. biodiversity aspects. Still, the importance of those forests for climate change mitigation compared to managed forests is under controversial debate. We evaluate the adequacy of referring to CO2 flux measurements alone and include external impacts on growth (nitrogen immissions, increasing temperatures, CO2 enrichment, changed precipitation patterns) for an evaluation of central European forests in this context. We deduce that the use of CO2 flux measurements alone does not allow conclusions on a superiority of unmanaged to managed forests for mitigation goals. This is based on the critical consideration of uncertainties and the application of system boundaries. Furthermore, the consideration of wood products for material and energetic substitution obviously overrules the mitigation potential of unmanaged forests. Moreover, impacts of nitrogen immissions, CO2 enrichment of the atmosphere, increasing temperatures and changed precipitation patterns obviously lead to a meaningful increase in growth, even in forests of higher age. An impact of unmanaged forests on climate change mitigation cannot be valued by CO2 flux measurements alone. Further research is needed on cause and effect relationships between management practices and carbon stocks in different compartments of forest ecosystems in order to account for human-induced changes. Unexpected growth rates in old-growth forests - managed or not - can obviously be related to external impacts and additionally to management impacts. This should lead to the reconsideration of forest management strategies.

Peatland simulator connecting drainage, nutrient cycling, forest growth, economy and GHG efflux in boreal and tropical peatlands

NASA Astrophysics Data System (ADS)

Lauren, Ari; Hökkä, Hannu; Launiainen, Samuli; Palviainen, Marjo; Lehtonen, Aleksi

2016-04-01

Forest growth in peatlands is nutrient limited; principal source of nutrients is the decomposition of organic matter. Excess water decreases O2 diffusion and slows down the nutrient release. Drainage increases organic matter decomposition, CO2 efflux, and nutrient supply, and enhances the growth of forest. Profitability depends on costs, gained extra yield and its allocation into timber assortments, and the rate of interest. We built peatland simulator Susi to define and parameterize these interrelations. We applied Susi-simulator to compute water and nutrient processes, forest growth, and CO2 efflux of forested drained peatland. The simulator computes daily water fluxes and storages in two dimensions for a peatland forest strip located between drainage ditches. The CO2 efflux is made proportional to peat bulk density, soil temperature and O2 availability. Nutrient (N, P, K) release depends on decomposition and peat nutrient content. Growth limiting nutrient is detected by comparing the need and supply of nutrients. Increased supply of growth limiting nutrient is used to quantify the forest growth response to improved drainage. The extra yield is allocated into pulpwood and sawlogs based on volume of growing stock. The net present values of ditch cleaning operation and the gained extra yield are computed under different rates of interest to assess the profitability of the ditch cleaning. The hydrological sub-models of Susi-simulator were first parameterized using daily water flux data from Hyytiälä SMEAR II-site, after which the predictions were tested against independent hydrologic data from two drained peatland forests in Southern Finland. After verification of the hydrologic model, the CO2 efflux, nutrient release and forest growth proportionality hypothesis was tested and model performance validated against long-term forest growth and groundwater level data from 69 forested peatland sample plots in Central Finland. The results showed a clear relation between

Stand structure in eastside old-growth ponderosa pine forests of Oregon and northern California.

Treesearch

Andrew Youngblood; Timothy Max; Kent Coe

2004-01-01

Quantitative metrics of horizontal and vertical structural attributes in eastside old-growth ponderosa pine (Pinus ponderosa P. and C. Lawson var. ponderosa) forests were measured to guide the design of restoration prescriptions. The age, size structure, and the spatial patterns were investigated in old-growth ponderosa pine forests at three...

Diverging climate trends in Mongolian taiga forests influence growth and regeneration of Larix sibirica

PubMed Central

Dulamsuren, Choimaa; Khishigjargal, Mookhor; Leuschner, Hanns Hubert; Leuschner, Christoph

2010-01-01

Central and semiarid north-eastern Asia was subject to twentieth century warming far above the global average. Since forests of this region occur at their drought limit, they are particularly vulnerable to climate change. We studied the regional variations of temperature and precipitation trends and their effects on tree growth and forest regeneration in Mongolia. Tree-ring series from more than 2,300 trees of Siberian larch (Larix sibirica) collected in four regions of Mongolia’s forest zone were analyzed and related to available weather data. Climate trends underlie a remarkable regional variation leading to contrasting responses of tree growth in taiga forests even within the same mountain system. Within a distance of a few hundred kilometers (140–490 km), areas with recently reduced growth and regeneration of larch alternated with regions where these parameters remained constant or even increased. Reduced productivity could be correlated with increasing summer temperatures and decreasing precipitation; improved growth conditions were found at increasing precipitation, but constant summer temperatures. An effect of increasing winter temperatures on tree-ring width or forest regeneration was not detectable. Since declines of productivity and regeneration are more widespread in the Mongolian taiga than the opposite trend, a net loss of forests is likely to occur in the future, as strong increases in temperature and regionally differing changes in precipitation are predicted for the twenty-first century. PMID:20571829

Diverging climate trends in Mongolian taiga forests influence growth and regeneration of Larix sibirica.

PubMed

Dulamsuren, Choimaa; Hauck, Markus; Khishigjargal, Mookhor; Leuschner, Hanns Hubert; Leuschner, Christoph

2010-08-01

Central and semiarid north-eastern Asia was subject to twentieth century warming far above the global average. Since forests of this region occur at their drought limit, they are particularly vulnerable to climate change. We studied the regional variations of temperature and precipitation trends and their effects on tree growth and forest regeneration in Mongolia. Tree-ring series from more than 2,300 trees of Siberian larch (Larix sibirica) collected in four regions of Mongolia's forest zone were analyzed and related to available weather data. Climate trends underlie a remarkable regional variation leading to contrasting responses of tree growth in taiga forests even within the same mountain system. Within a distance of a few hundred kilometers (140-490 km), areas with recently reduced growth and regeneration of larch alternated with regions where these parameters remained constant or even increased. Reduced productivity could be correlated with increasing summer temperatures and decreasing precipitation; improved growth conditions were found at increasing precipitation, but constant summer temperatures. An effect of increasing winter temperatures on tree-ring width or forest regeneration was not detectable. Since declines of productivity and regeneration are more widespread in the Mongolian taiga than the opposite trend, a net loss of forests is likely to occur in the future, as strong increases in temperature and regionally differing changes in precipitation are predicted for the twenty-first century.

Influence of competition and age on tree growth in structurally complex old-growth forests in northern Minnesota, USA

Treesearch

Tuomas Aakala; Shawn Fraver; Anthony W. D' Amato; Brian J. Palik

2013-01-01

Factors influencing tree growth in structurally complex forests remain poorly understood. Here we assessed the influence of competition on Pinus resinosa (n = 224) and Pinus strobus (n = 90) growth in four old-growth stands in Minnesota, using mixed effects models. A subset of trees, with...

Diverse growth trends and climate responses across Eurasia’s boreal forest

NASA Astrophysics Data System (ADS)

Hellmann, Lena; Agafonov, Leonid; Charpentier Ljungqvist, Fredrik; Churakova (Sidorova, Olga; Düthorn, Elisabeth; Esper, Jan; Hülsmann, Lisa; Kirdyanov, Alexander V.; Moiseev, Pavel; Myglan, Vladimir S.; Nikolaev, Anatoly N.; Reinig, Frederick; Schweingruber, Fritz H.; Solomina, Olga; Tegel, Willy; Büntgen, Ulf

2016-07-01

The area covered by boreal forests accounts for ˜16% of the global and 22% of the Northern Hemisphere landmass. Changes in the productivity and functioning of this circumpolar biome not only have strong effects on species composition and diversity at regional to larger scales, but also on the Earth’s carbon cycle. Although temporal inconsistency in the response of tree growth to temperature has been reported from some locations at the higher northern latitudes, a systematic dendroecological network assessment is still missing for most of the boreal zone. Here, we analyze the geographical patterns of changes in summer temperature and precipitation across northern Eurasia >60 °N since 1951 AD, as well as the growth trends and climate responses of 445 Pinus, Larix and Picea ring width chronologies in the same area and period. In contrast to widespread summer warming, fluctuations in precipitation and tree growth are spatially more diverse and overall less distinct. Although the influence of summer temperature on ring formation is increasing with latitude and distinct moisture effects are restricted to a few southern locations, growth sensitivity to June-July temperature variability is only significant at 16.6% of all sites (p ≤ 0.01). By revealing complex climate constraints on the productivity of Eurasia’s northern forests, our results question the a priori suitability of boreal tree-ring width chronologies for reconstructing summer temperatures. This study further emphasizes regional climate differences and their role on the dynamics of boreal ecosystems, and also underlines the importance of free data access to facilitate the compilation and evaluation of massively replicated and updated dendroecological networks.

A dynamic ecosystem growth model for forests at high complexity structure

NASA Astrophysics Data System (ADS)

Collalti, A.; Perugini, L.; Chiti, T.; Matteucci, G.; Oriani, A.; Santini, M.; Papale, D.; Valentini, R.

2012-04-01

Forests ecosystem play an important role in carbon cycle, biodiversity conservation and for other ecosystem services and changes in their structure and status perturb a delicate equilibrium that involves not only vegetation components but also biogeochemical cycles and global climate. The approaches to determine the magnitude of these effects are nowadays various and one of those include the use of models able to simulate structural changes and the variations in forests yield The present work shows the development of a forest dynamic model, on ecosystem spatial scale using the well known light use efficiency to determine Gross Primary Production. The model is predictive and permits to simulate processes that determine forest growth, its dynamic and the effects of forest management using eco-physiological parameters easy to be assessed and to be measured. The model has been designed to consider a tri-dimensional cell structure composed by different vertical layers depending on the forest type that has to be simulated. These features enable the model to work on multi-layer and multi-species forest types, typical of Mediterranean environment, at the resolution of one hectare and at monthly time-step. The model simulates, for each layer, a value of available Photosynthetic Active Radiation (PAR) through Leaf Area Index, Light Extinction Coefficient and cell coverage, the transpiration rate that is closely linked to the intercepted light and the evaporation from soil. Using this model it is possible to evaluate the possible impacts of climate change on forests that may result in decrease or increase of productivity as well as the feedback of one or more dominated layers in terms of CO2 uptake in a forest stand and the effects of forest management activities during the forest harvesting cycle. The model has been parameterised, validated and applied in a multi-layer, multi-age and multi-species Italian turkey oak forest (Q. cerris L., C. betulus L. and C. avellana L

Tree growth acceleration and expansion of alpine forests: The synergistic effect of atmospheric and edaphic change.

PubMed

Silva, Lucas C R; Sun, Geng; Zhu-Barker, Xia; Liang, Qianlong; Wu, Ning; Horwath, William R

2016-08-01

Many forest ecosystems have experienced recent declines in productivity; however, in some alpine regions, tree growth and forest expansion are increasing at marked rates. Dendrochronological analyses at the upper limit of alpine forests in the Tibetan Plateau show a steady increase in tree growth since the early 1900s, which intensified during the 1930s and 1960s, and have reached unprecedented levels since 1760. This recent growth acceleration was observed in small/young and large/old trees and coincided with the establishment of trees outside the forest range, reflecting a connection between the physiological performance of dominant species and shifts in forest distribution. Measurements of stable isotopes (carbon, oxygen, and nitrogen) in tree rings indicate that tree growth has been stimulated by the synergistic effect of rising atmospheric CO2 and a warming-induced increase in water and nutrient availability from thawing permafrost. These findings illustrate the importance of considering soil-plant-atmosphere interactions to understand current and anticipate future changes in productivity and distribution of forest ecosystems.

Tree growth acceleration and expansion of alpine forests: The synergistic effect of atmospheric and edaphic change

PubMed Central

Silva, Lucas C. R.; Sun, Geng; Zhu-Barker, Xia; Liang, Qianlong; Wu, Ning; Horwath, William R.

2016-01-01

Many forest ecosystems have experienced recent declines in productivity; however, in some alpine regions, tree growth and forest expansion are increasing at marked rates. Dendrochronological analyses at the upper limit of alpine forests in the Tibetan Plateau show a steady increase in tree growth since the early 1900s, which intensified during the 1930s and 1960s, and have reached unprecedented levels since 1760. This recent growth acceleration was observed in small/young and large/old trees and coincided with the establishment of trees outside the forest range, reflecting a connection between the physiological performance of dominant species and shifts in forest distribution. Measurements of stable isotopes (carbon, oxygen, and nitrogen) in tree rings indicate that tree growth has been stimulated by the synergistic effect of rising atmospheric CO2 and a warming-induced increase in water and nutrient availability from thawing permafrost. These findings illustrate the importance of considering soil-plant-atmosphere interactions to understand current and anticipate future changes in productivity and distribution of forest ecosystems. PMID:27652334

Pervasive growth reduction in Norway spruce forests following wind disturbance.

PubMed

Seidl, Rupert; Blennow, Kristina

2012-01-01

In recent decades the frequency and severity of natural disturbances by e.g., strong winds and insect outbreaks has increased considerably in many forest ecosystems around the world. Future climate change is expected to further intensify disturbance regimes, which makes addressing disturbances in ecosystem management a top priority. As a prerequisite a broader understanding of disturbance impacts and ecosystem responses is needed. With regard to the effects of strong winds--the most detrimental disturbance agent in Europe--monitoring and management has focused on structural damage, i.e., tree mortality from uprooting and stem breakage. Effects on the functioning of trees surviving the storm (e.g., their productivity and allocation) have been rarely accounted for to date. Here we show that growth reduction was significant and pervasive in a 6.79 million hectare forest landscape in southern Sweden following the storm Gudrun (January 2005). Wind-related growth reduction in Norway spruce (Picea abies (L.) Karst.) forests surviving the storm exceeded 10% in the worst hit regions, and was closely related to maximum gust wind speed (R(2) = 0.849) and structural wind damage (R(2) = 0.782). At the landscape scale, wind-related growth reduction amounted to 3.0 million m(3) in the three years following Gudrun. It thus exceeds secondary damage from bark beetles after Gudrun as well as the long-term average storm damage from uprooting and stem breakage in Sweden. We conclude that the impact of strong winds on forest ecosystems is not limited to the immediately visible area of structural damage, and call for a broader consideration of disturbance effects on ecosystem structure and functioning in the context of forest management and climate change mitigation.

Pervasive Growth Reduction in Norway Spruce Forests following Wind Disturbance

PubMed Central

Seidl, Rupert; Blennow, Kristina

2012-01-01

Background In recent decades the frequency and severity of natural disturbances by e.g., strong winds and insect outbreaks has increased considerably in many forest ecosystems around the world. Future climate change is expected to further intensify disturbance regimes, which makes addressing disturbances in ecosystem management a top priority. As a prerequisite a broader understanding of disturbance impacts and ecosystem responses is needed. With regard to the effects of strong winds – the most detrimental disturbance agent in Europe – monitoring and management has focused on structural damage, i.e., tree mortality from uprooting and stem breakage. Effects on the functioning of trees surviving the storm (e.g., their productivity and allocation) have been rarely accounted for to date. Methodology/Principal Findings Here we show that growth reduction was significant and pervasive in a 6.79·million hectare forest landscape in southern Sweden following the storm Gudrun (January 2005). Wind-related growth reduction in Norway spruce (Picea abies (L.) Karst.) forests surviving the storm exceeded 10% in the worst hit regions, and was closely related to maximum gust wind speed (R2 = 0.849) and structural wind damage (R2 = 0.782). At the landscape scale, wind-related growth reduction amounted to 3.0 million m3 in the three years following Gudrun. It thus exceeds secondary damage from bark beetles after Gudrun as well as the long-term average storm damage from uprooting and stem breakage in Sweden. Conclusions/Significance We conclude that the impact of strong winds on forest ecosystems is not limited to the immediately visible area of structural damage, and call for a broader consideration of disturbance effects on ecosystem structure and functioning in the context of forest management and climate change mitigation. PMID:22413012

Climate, Tree Growth, Forest Drought Stress, and Tree Mortality in Forests of Western North America: Long-Term Patterns and Recent Trends

NASA Astrophysics Data System (ADS)

Allen, C. D.; Williams, P.

2012-12-01

Ongoing climate changes are increasingly affecting the world's forests, particularly including high latitude and high elevation coniferous forests. Although forest growth has improved in some regions due to greater growing season length and warmth (perhaps along with increased atmospheric CO2 or N), large growth declines or increased mortality from droughts or hotter temperatures also are being observed. We present and interpret information on regional variation in climate-tree growth relationships and trends, and on patterns and trends of climate-related forest disturbances, from western North America. From 235 tree-ring chronologies in the Southwest US we show that tree-ring growth records from warmer southwestern sites are more sensitive to temperature than tree-ring growth records from cooler southwestern sites. Assessment of 59 tree-ring records from 11 species in the Cascade Mountains of the Pacific Northwest shows that trees growing in cool places respond positively to increased temperature and trees in warm places respond negatively, implying that trees historically not sensitive to temperature may become sensitive as mean temperatures warm. An analysis of 59 white spruce populations in Alaska supports the hypothesis that warming has caused tree growth to lose sensitivity to cold temperatures. Comparing ring widths to temperature during just the coldest 50% of years during the 20th century, tree growth was sensitive to cold temperatures, and this effect was strongest at the coldest sites; whereas during the warmest 50% of years, trees were not at all sensitive to cold temperatures, even at the cold sites. Drought and vapor pressure deficit are among the variables that emerge as being increasingly important to these Alaska boreal forests as mean temperatures rise. Most recently, from 346 tree-ring chronologies in the Southwest US we establish a tree-ring-based Forest Drought Stress Index (FDSI) for the three most widespread conifer species (Pinus edulis

Can traits predict individual growth performance? A test in a hyperdiverse tropical forest.

PubMed

Poorter, Lourens; Castilho, Carolina V; Schietti, Juliana; Oliveira, Rafael S; Costa, Flávia R C

2018-07-01

The functional trait approach has, as a central tenet, that plant traits are functional and shape individual performance, but this has rarely been tested in the field. Here, we tested the individual-based trait approach in a hyperdiverse Amazonian tropical rainforest and evaluated intraspecific variation in trait values, plant strategies at the individual level, and whether traits are functional and predict individual performance. We evaluated > 1300 tree saplings belonging to > 383 species, measured 25 traits related to growth and defense, and evaluated the effects of environmental conditions, plant size, and traits on stem growth. A total of 44% of the trait variation was observed within species, indicating a strong potential for acclimation. Individuals showed two strategy spectra, related to tissue toughness and organ size vs leaf display. In this nutrient- and light-limited forest, traits measured at the individual level were surprisingly poor predictors of individual growth performance because of convergence of traits and growth rates. Functional trait approaches based on individuals or species are conceptually fundamentally different: the species-based approach focuses on the potential and the individual-based approach on the realized traits and growth rates. Counterintuitively, the individual approach leads to a poor prediction of individual performance, although it provides a more realistic view on community dynamics. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Influence of repeated prescribed fire on tree growth and mortality in Pinus resinosa forests, northern Minnesota

USGS Publications Warehouse

Bottero, Alessandra; D'Amato, Anthony W.; Palik, Brian J.; Kern, Christel C.; Bradford, John B.; Scherer, Sawyer S.

2017-01-01

Prescribed fire is widely used for ecological restoration and fuel reduction in fire-dependent ecosystems, most of which are also prone to drought. Despite the importance of drought in fire-adapted forests, little is known about cumulative effects of repeated prescribed burning on tree growth and related response to drought. Using dendrochronological data in red pine (Pinus resinosa Ait.)-dominated forests in northern Minnesota, USA, we examined growth responses before and after understory prescribed fires between 1960 and 1970, to assess whether repeated burning influences growth responses of overstory trees and vulnerability of overstory tree growth to drought. We found no difference in tree-level growth vulnerability to drought, expressed as growth resistance, resilience, and recovery, between areas receiving prescribed fire treatments and untreated forests. Annual mortality rates during the period of active burning were also low (less than 2%) in all treatments. These findings indicate that prescribed fire can be effectively integrated into management plans and climate change adaptation strategies for red pine forest ecosystems without significant short- or long-term negative consequences for growth or mortality rates of overstory trees.

Alternative definitions of growth and removals and implications for forest sustainability

Treesearch

Paul C. Van Deusen; Francis A. Roesch

2008-01-01

Alternative definitions for growth and removals from a forest being monitored over time are discussed. It is shown that the definitions that are used in practice may not be what one would expect and estimates can vary substantially under alternative definitions. This can result in conclusions about forest sustainability that may be misleading. Alternative definitions...

Estimating the capital recovery costs of managing for old growth forests

Treesearch

Chris B. LeDoux

2004-01-01

Contemporary forest management practices require a variety of retention treatments that leave clumps, blocks, strips, or zones of existing forest cover in order to achieve a wide array of biodiversity, wildlife, visual, ecological, and old growth creation/conservation objectives. Some of these practices call for leaving a portion or portions of existing stands for...

Back to the future: assessing accuracy and sensitivity of a forest growth model

Treesearch

Susan Hummel; Paul Meznarich

2014-01-01

The Forest Vegetation Simulator (FVS) is a widely used computer model that projects forest growth and predicts the effects of disturbances such as fire, insects, harvests, or disease. Land managers often use these projections to decide among silvicultural options and estimate the potential effects of these options on forest conditions. Despite FVS's popularity,...

Foliar and ecosystem respiration in an old-growth tropical rain forest

Treesearch

Molly A. Cavaleri; Steven F. Oberbauer; Michael G. Ryan

2008-01-01

Foliar respiration is a major component of ecosystem respiration, yet extrapolations are often uncertain in tropical forests because of indirect estimates of leaf area index (LAI).A portable tower was used to directly measure LAI and night-time foliar respiration from 52 vertical transects throughout an old-growth tropical rain forest in Costa Rica. In this study, we (...

Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics

PubMed Central

Chazdon, Robin L.; Broadbent, Eben N.; Rozendaal, Danaë M. A.; Bongers, Frans; Zambrano, Angélica María Almeyda; Aide, T. Mitchell; Balvanera, Patricia; Becknell, Justin M.; Boukili, Vanessa; Brancalion, Pedro H. S.; Craven, Dylan; Almeida-Cortez, Jarcilene S.; Cabral, George A. L.; de Jong, Ben; Denslow, Julie S.; Dent, Daisy H.; DeWalt, Saara J.; Dupuy, Juan M.; Durán, Sandra M.; Espírito-Santo, Mario M.; Fandino, María C.; César, Ricardo G.; Hall, Jefferson S.; Hernández-Stefanoni, José Luis; Jakovac, Catarina C.; Junqueira, André B.; Kennard, Deborah; Letcher, Susan G.; Lohbeck, Madelon; Martínez-Ramos, Miguel; Massoca, Paulo; Meave, Jorge A.; Mesquita, Rita; Mora, Francisco; Muñoz, Rodrigo; Muscarella, Robert; Nunes, Yule R. F.; Ochoa-Gaona, Susana; Orihuela-Belmonte, Edith; Peña-Claros, Marielos; Pérez-García, Eduardo A.; Piotto, Daniel; Powers, Jennifer S.; Rodríguez-Velazquez, Jorge; Romero-Pérez, Isabel Eunice; Ruíz, Jorge; Saldarriaga, Juan G.; Sanchez-Azofeifa, Arturo; Schwartz, Naomi B.; Steininger, Marc K.; Swenson, Nathan G.; Uriarte, Maria; van Breugel, Michiel; van der Wal, Hans; Veloso, Maria D. M.; Vester, Hans; Vieira, Ima Celia G.; Bentos, Tony Vizcarra; Williamson, G. Bruce; Poorter, Lourens

2016-01-01

Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km2 of land (28.1% of the total study area). Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from 1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forest management, natural regeneration of second-growth forests provides a low-cost mechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services. PMID:27386528

Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics.

PubMed

Chazdon, Robin L; Broadbent, Eben N; Rozendaal, Danaë M A; Bongers, Frans; Zambrano, Angélica María Almeyda; Aide, T Mitchell; Balvanera, Patricia; Becknell, Justin M; Boukili, Vanessa; Brancalion, Pedro H S; Craven, Dylan; Almeida-Cortez, Jarcilene S; Cabral, George A L; de Jong, Ben; Denslow, Julie S; Dent, Daisy H; DeWalt, Saara J; Dupuy, Juan M; Durán, Sandra M; Espírito-Santo, Mario M; Fandino, María C; César, Ricardo G; Hall, Jefferson S; Hernández-Stefanoni, José Luis; Jakovac, Catarina C; Junqueira, André B; Kennard, Deborah; Letcher, Susan G; Lohbeck, Madelon; Martínez-Ramos, Miguel; Massoca, Paulo; Meave, Jorge A; Mesquita, Rita; Mora, Francisco; Muñoz, Rodrigo; Muscarella, Robert; Nunes, Yule R F; Ochoa-Gaona, Susana; Orihuela-Belmonte, Edith; Peña-Claros, Marielos; Pérez-García, Eduardo A; Piotto, Daniel; Powers, Jennifer S; Rodríguez-Velazquez, Jorge; Romero-Pérez, Isabel Eunice; Ruíz, Jorge; Saldarriaga, Juan G; Sanchez-Azofeifa, Arturo; Schwartz, Naomi B; Steininger, Marc K; Swenson, Nathan G; Uriarte, Maria; van Breugel, Michiel; van der Wal, Hans; Veloso, Maria D M; Vester, Hans; Vieira, Ima Celia G; Bentos, Tony Vizcarra; Williamson, G Bruce; Poorter, Lourens

2016-05-01

Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km(2) of land (28.1% of the total study area). Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from 1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forest management, natural regeneration of second-growth forests provides a low-cost mechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services.

Assessing forest vulnerability to climate warming using a process-based model of tree growth: bad prospects for rear-edges.

PubMed

Sánchez-Salguero, Raúl; Camarero, Jesus Julio; Gutiérrez, Emilia; González Rouco, Fidel; Gazol, Antonio; Sangüesa-Barreda, Gabriel; Andreu-Hayles, Laia; Linares, Juan Carlos; Seftigen, Kristina

2017-07-01

Growth models can be used to assess forest vulnerability to climate warming. If global warming amplifies water deficit in drought-prone areas, tree populations located at the driest and southernmost distribution limits (rear-edges) should be particularly threatened. Here, we address these statements by analyzing and projecting growth responses to climate of three major tree species (silver fir, Abies alba; Scots pine, Pinus sylvestris; and mountain pine, Pinus uncinata) in mountainous areas of NE Spain. This region is subjected to Mediterranean continental conditions, it encompasses wide climatic, topographic and environmental gradients, and, more importantly, it includes rear-edges of the continuous distributions of these tree species. We used tree-ring width data from a network of 110 forests in combination with the process-based Vaganov-Shashkin-Lite growth model and climate-growth analyses to forecast changes in tree growth during the 21st century. Climatic projections were based on four ensembles CO 2 emission scenarios. Warm and dry conditions during the growing season constrain silver fir and Scots pine growth, particularly at the species rear-edge. By contrast, growth of high-elevation mountain pine forests is enhanced by climate warming. The emission scenario (RCP 8.5) corresponding to the most pronounced warming (+1.4 to 4.8 °C) forecasted mean growth reductions of -10.7% and -16.4% in silver fir and Scots pine, respectively, after 2050. This indicates that rising temperatures could amplify drought stress and thus constrain the growth of silver fir and Scots pine rear-edge populations growing at xeric sites. Contrastingly, mountain pine growth is expected to increase by +12.5% due to a longer and warmer growing season. The projections of growth reduction in silver fir and Scots pine portend dieback and a contraction of their species distribution areas through potential local extinctions of the most vulnerable driest rear-edge stands. Our modeling

Long-term growth decline in Toona ciliata in a moist tropical forest in Bangladesh: Impact of global warming

NASA Astrophysics Data System (ADS)

Rahman, Mizanur; Islam, Rofiqul; Islam, Mahmuda

2017-04-01

Tropical forests are carbon rich ecosystems and small changes in tropical forest tree growth substantially influence the global carbon cycle. Forest monitoring studies report inconsistent growth changes in tropical forest trees over the past decades. Most of the studies highlighted changes in the forest level carbon gain, neglecting the species-specific growth changes which ultimately determine community-level responses. Tree-ring analysis can provide historical data on species-specific tree growth with annual resolution. Such studies are inadequate in Bangladesh, which is one of the most climate sensitive regions in the tropics. In this study, we investigated long-term growth rates of Toona ciliata in a moist tropical forest of Bangladesh by using tree-ring analysis. We sampled 50 trees of varying size, obtained increment cores from these trees and measured tree-ring width. Analyses of growth patterns revealed size-dependent growth increments. After correcting for the effect of tree size on tree growth (ontogenetic changes) by two different methods we found declining growth rates in T. ciliata from 1960 to 2013. Standardized ring-width index (RWI) was strongly negatively correlated with annual mean and maximum temperatures suggesting that rising temperature might cause the observed growth decline in T. ciliata. Assuming that global temperatures will rise at the current rate, the observed growth decline is assumed to continue. The analysis of stable carbon and oxygen isotopes may reveal more insight on the physiological response of this species to future climatic changes.

No growth stimulation of Canada's boreal forest under half-century of combined warming and CO2 fertilization.

PubMed

Girardin, Martin P; Bouriaud, Olivier; Hogg, Edward H; Kurz, Werner; Zimmermann, Niklaus E; Metsaranta, Juha M; de Jong, Rogier; Frank, David C; Esper, Jan; Büntgen, Ulf; Guo, Xiao Jing; Bhatti, Jagtar

2016-12-27

Considerable evidence exists that current global temperatures are higher than at any time during the past millennium. However, the long-term impacts of rising temperatures and associated shifts in the hydrological cycle on the productivity of ecosystems remain poorly understood for mid to high northern latitudes. Here, we quantify species-specific spatiotemporal variability in terrestrial aboveground biomass stem growth across Canada's boreal forests from 1950 to the present. We use 873 newly developed tree-ring chronologies from Canada's National Forest Inventory, representing an unprecedented degree of sampling standardization for a large-scale dendrochronological study. We find significant regional- and species-related trends in growth, but the positive and negative trends compensate each other to yield no strong overall trend in forest growth when averaged across the Canadian boreal forest. The spatial patterns of growth trends identified in our analysis were to some extent coherent with trends estimated by remote sensing, but there are wide areas where remote-sensing information did not match the forest growth trends. Quantifications of tree growth variability as a function of climate factors and atmospheric CO 2 concentration reveal strong negative temperature and positive moisture controls on spatial patterns of tree growth rates, emphasizing the ecological sensitivity to regime shifts in the hydrological cycle. An enhanced dependence of forest growth on soil moisture during the late-20th century coincides with a rapid rise in summer temperatures and occurs despite potential compensating effects from increased atmospheric CO 2 concentration.

Quantifying climate-growth relationships at the stand level in a mature mixed-species conifer forest.

PubMed

Teets, Aaron; Fraver, Shawn; Weiskittel, Aaron R; Hollinger, David Y

2018-03-11

A range of environmental factors regulate tree growth; however, climate is generally thought to most strongly influence year-to-year variability in growth. Numerous dendrochronological (tree-ring) studies have identified climate factors that influence year-to-year variability in growth for given tree species and location. However, traditional dendrochronology methods have limitations that prevent them from adequately assessing stand-level (as opposed to species-level) growth. We argue that stand-level growth analyses provide a more meaningful assessment of forest response to climate fluctuations, as well as the management options that may be employed to sustain forest productivity. Working in a mature, mixed-species stand at the Howland Research Forest of central Maine, USA, we used two alternatives to traditional dendrochronological analyses by (1) selecting trees for coring using a stratified (by size and species), random sampling method that ensures a representative sample of the stand, and (2) converting ring widths to biomass increments, which once summed, produced a representation of stand-level growth, while maintaining species identities or canopy position if needed. We then tested the relative influence of seasonal climate variables on year-to-year variability in the biomass increment using generalized least squares regression, while accounting for temporal autocorrelation. Our results indicate that stand-level growth responded most strongly to previous summer and current spring climate variables, resulting from a combination of individualistic climate responses occurring at the species- and canopy-position level. Our climate models were better fit to stand-level biomass increment than to species-level or canopy-position summaries. The relative growth responses (i.e., percent change) predicted from the most influential climate variables indicate stand-level growth varies less from to year-to-year than species-level or canopy-position growth responses. By

Spatial relationship of biomass and species distribution in an old-growth Pseudotsuga Tsuga forest.

Treesearch

Jiquan Chen; Bo Song; Mark Rudnicki; Melinda Moeur; Ken Bible; Malcolm North; Dave C. Shaw; Jerry F. Franklin; Dave M. Braun

2003-01-01

Old-growth forests are known for their complex and variable structure and function. In a 12-ha plot (300 m x 400 m) of an old-growth Douglas-fir forest within the T.T. Munger Research Natural Area in southern Washington, we mapped and recorded live/dead condition, species, and diameter at breast height to address the following objectives: (1) to quantify the...

An evaluation of three growth and yield simulators for even-aged hardwood forests of the mid-Appalachian region

Treesearch

John R. Brooks; Gary W. Miller

2011-01-01

Data from even-aged hardwood stands in four ecoregions across the mid-Appalachian region were used to test projection accuracy for three available growth and yield software systems: SILVAH, the Forest Vegetation Simulator, and the Stand Damage Model. Average root mean squared error (RMSE) ranged from 20 to 140 percent of actual trees per acre while RMSE ranged from 2...

Attaining the canopy in dry and moist tropical forests: strong differences in tree growth trajectories reflect variation in growing conditions.

PubMed

Brienen, Roel J W; Zuidema, Pieter A; Martínez-Ramos, Miguel

2010-06-01

Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees--those that have not attained the canopy--are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests.

Accuracy and equivalence testing of crown ratio models and assessment of their impact on diameter growth and basal area increment predictions of two variants of the Forest Vegetation Simulator

Treesearch

Laura P. Leites; Andrew P. Robinson; Nicholas L. Crookston

2009-01-01

Diameter growth (DG) equations in many existing forest growth and yield models use tree crown ratio (CR) as a predictor variable. Where CR is not measured, it is estimated from other measured variables. We evaluated CR estimation accuracy for the models in two Forest Vegetation Simulator variants: the exponential and the logistic CR models used in the North...

Particle growth in an isoprene-rich forest: Influences of urban, wildfire, and biogenic air masses

NASA Astrophysics Data System (ADS)

Gunsch, Matthew J.; Schmidt, Stephanie A.; Gardner, Daniel J.; Bondy, Amy L.; May, Nathaniel W.; Bertman, Steven B.; Pratt, Kerri A.; Ault, Andrew P.

2018-04-01

Growth of freshly nucleated particles is an important source of cloud condensation nuclei (CCN) and has been studied within a variety of environments around the world. However, there remains uncertainty regarding the sources of the precursor gases leading to particle growth, particularly in isoprene-rich forests. In this study, particle growth events were observed from the 14 total events (31% of days) during summer measurements (June 24 - August 2, 2014) at the Program for Research on Oxidants PHotochemistry, Emissions, and Transport (PROPHET) tower within the forested University of Michigan Biological Station located in northern Michigan. Growth events were observed within long-range transported air masses from urban areas, air masses impacted by wildfires, as well as stagnant, forested/regional air masses. Growth events observed during urban-influenced air masses were prevalent, with presumably high oxidant levels, and began midday during periods of high solar radiation. This suggests that increased oxidation of biogenic volatile organic compounds (BVOCs) likely contributed to the highest observed particle growth in this study (8 ± 2 nm h-1). Growth events during wildfire-influenced air masses were observed primarily at night and had slower growth rates (3 ± 1 nm h-1). These events were likely influenced by increased SO2, O3, and NO2 transported within the smoke plumes, suggesting a role of NO3 oxidation in the production of semi-volatile compounds. Forested/regional air mass growth events likely occurred due to the oxidation of regionally emitted BVOCs, including isoprene, monoterpenes, and sesquiterpenes, which facilitated multiday growth events also with slower rates (3 ± 2 nm h-1). Intense sulfur, carbon, and oxygen signals in individual particles down to 20 nm, analyzed by transmission electron microscopy with energy dispersive X-ray spectroscopy (TEM-EDX), suggest that H2SO4 and secondary organic aerosol contributed to particle growth. Overall, aerosol

Climate indices strongly influence old-growth forest carbon exchange

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wharton, Sonia; Falk, Matthias

We present a decade and a half (1998–2013) of carbon dioxide fluxes from an old-growth stand in the American Pacific Northwest to identify ecosystem-level responses to Pacific teleconnection patterns, including the El Niño/Southern Oscillation (ENSO). This study provides the longest, continuous record of old-growth eddy flux data to date from one of the longest running Fluxnet stations in the world. From 1998 to 2013, average annual net ecosystem exchange (F NEE) at Wind River AmeriFlux was –32 ± 84 g C m –2 yr –1 indicating that the late seral forest is on average a small net sink of atmosphericmore » carbon. However, interannual variability is high (>300 g C m –2 yr –1) and shows that the stand switches from net carbon sink to source in response to climate drivers associated with ENSO. The old-growth forest is a much stronger sink during La Niña years (mean F NEE = –90 g C m –2 yr –1) than during El Niño when the stand turns carbon neutral or into a small net carbon source (mean F NEE = +17 g C m –2 yr –1). Forest inventory data dating back to the 1930s show a similar correlation with the lower frequency Pacific North American (PNA) and Pacific Decadal Oscillation (PDO) whereby higher aboveground net primary productivity (F ANPP) is associated with cool phases of both the PNA and PDO. Furthermore, these measurements add evidence that carbon exchange in old-growth stands may be more sensitive to climate variability across shorter time scales than once thought.« less

Climate indices strongly influence old-growth forest carbon exchange

DOE PAGES

Wharton, Sonia; Falk, Matthias

2016-04-13

We present a decade and a half (1998–2013) of carbon dioxide fluxes from an old-growth stand in the American Pacific Northwest to identify ecosystem-level responses to Pacific teleconnection patterns, including the El Niño/Southern Oscillation (ENSO). This study provides the longest, continuous record of old-growth eddy flux data to date from one of the longest running Fluxnet stations in the world. From 1998 to 2013, average annual net ecosystem exchange (F NEE) at Wind River AmeriFlux was –32 ± 84 g C m –2 yr –1 indicating that the late seral forest is on average a small net sink of atmosphericmore » carbon. However, interannual variability is high (>300 g C m –2 yr –1) and shows that the stand switches from net carbon sink to source in response to climate drivers associated with ENSO. The old-growth forest is a much stronger sink during La Niña years (mean F NEE = –90 g C m –2 yr –1) than during El Niño when the stand turns carbon neutral or into a small net carbon source (mean F NEE = +17 g C m –2 yr –1). Forest inventory data dating back to the 1930s show a similar correlation with the lower frequency Pacific North American (PNA) and Pacific Decadal Oscillation (PDO) whereby higher aboveground net primary productivity (F ANPP) is associated with cool phases of both the PNA and PDO. Furthermore, these measurements add evidence that carbon exchange in old-growth stands may be more sensitive to climate variability across shorter time scales than once thought.« less

Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality

USGS Publications Warehouse

Foster, Jane R.; D'Amato, Anthony W.; Bradford, John B.

2014-01-01

Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with a census tree-ring data set from eight temperate forest types to reconstruct stand-level biomass increments (in Minnesota, USA). We compared growth patterns among mortality models, forest types and stands. Timing of peak biomass growth varied significantly among mortality models, peaking 20–30 years earlier when mortality was random with respect to tree growth and size, than when mortality favored slow-growing individuals. Random or u-shaped mortality (highest in small or large trees) produced peak growth 25–30 % higher than the surviving tree sample alone. Growth trends for even-aged, monospecific Pinus banksiana or Acer saccharum forests were similar to the early peak and decline expectation. However, we observed continually increasing biomass growth in older, low-productivity forests of Quercus rubra, Fraxinus nigra, and Thuja occidentalis. Tree-ring reconstructions estimated annual changes in live biomass growth and identified more diverse development patterns than previous methods. These detailed, long-term patterns of biomass development are crucial for detecting recent growth responses to global change and modeling future forest dynamics.

Protecting rare, old-growth, forest-associated species under the Survey and Manage program guidelines of the northwest forest plan.

Treesearch

Randy Molina; Bruce G. Marcot; Robin Lesher

2006-01-01

The Survey and Manage Program of the Northwest Forest Plan (MFP) represents an unparalleled attempt to protect rare, little-known species associated with late-successional and old-growth forests on more than 7.7 million ha of federal lands. Approximately 400 species of amphibians, bryophytes, fungi, lichens, mollusks, vascular plants, arthropod functional groups, and...

A Hierarchical Analysis of Tree Growth and Environmental Drivers Across Eastern US Temperate Forests

NASA Astrophysics Data System (ADS)

Mantooth, J.; Dietze, M.

2014-12-01

Improving predictions of how forests in the eastern United States will respond to future global change requires a better understanding of the drivers of variability in tree growth rates. Current inventory data lack the temporal resolution to characterize interannual variability, while existing growth records lack the extent required to assess spatial scales of variability. Therefore, we established a network of forest inventory plots across ten sites across the eastern US, and measured growth in adult trees using increment cores. Sites were chosen to maximize climate space explored, while within sites, plots were spread across primary environmental gradients to explore landscape-level variability in growth. Using the annual growth record available from tree cores, we explored the responses of trees to multiple environmental covariates over multiple spatial and temporal scales. We hypothesized that within and across sites growth rates vary among species, and that intraspecific growth rates increase with temperature along a species' range. We also hypothesized that trees show synchrony in growth responses to landscape-scale climatic changes. Initial analyses of growth increments indicate that across sites, trees with intermediate shade tolerance, e.g. Red Oak (Quercus rubra), tend to have the highest growth rates. At the site level, there is evidence for synchrony in response to large-scale climatic events (e.g. prolonged drought and above average temperatures). However, growth responses to climate at the landscape scale have yet to be detected. Our current analysis utilizes hierarchical Bayesian state-space modeling to focus on growth responses of adult trees to environmental covariates at multiple spatial and temporal scales. This predictive model of tree growth currently incorporates observed effects at the individual, plot, site, and landscape scale. Current analysis using this model shows a potential slowing of growth in the past decade for two sites in the

Low temperature growth of ultra-high mass density carbon nanotube forests on conductive supports

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugime, Hisashi; Esconjauregui, Santiago; Yang, Junwei

2013-08-12

We grow ultra-high mass density carbon nanotube forests at 450 °C on Ti-coated Cu supports using Co-Mo co-catalyst. X-ray photoelectron spectroscopy shows Mo strongly interacts with Ti and Co, suppressing both aggregation and lifting off of Co particles and, thus, promoting the root growth mechanism. The forests average a height of 0.38 μm and a mass density of 1.6 g cm{sup −3}. This mass density is the highest reported so far, even at higher temperatures or on insulators. The forests and Cu supports show ohmic conductivity (lowest resistance ∼22 kΩ), suggesting Co-Mo is useful for applications requiring forest growth onmore » conductors.« less

Western white pine growth relative to forest openings

Treesearch

Theresa B. Jain; Russell T. Graham; Penelope Morgan

2004-01-01

In northern Rocky Mountains moist forests, timber harvesting, fire exclusion, and an introduced stem disease have contributed to the decline in western white pine (Pinus monticola Dougl. ex D. Don) abundance (from 90% to 10% of the area). Relations between canopy openings (0.1-15 ha) and western white pine growth within different physical settings are identified....

Seedling growth responses to soil resources in the understory of a wet tropical forest.

PubMed

Holste, Ellen K; Kobe, Richard K; Vriesendorp, Corine F

2011-09-01

Plant growth responses to resources may be an important mechanism that influences species' distributions, coexistence, and community structure. Irradiance is considered the most important resource for seedling growth in the understory of wet tropical forests, but multiple soil nutrients and species have yet to be examined simultaneously with irradiance under field conditions. To identify potentially limiting resources, we modeled tree seedling growth as a function of irradiance and soil nutrients across five sites, spanning a soil fertility gradient in old-growth, wet tropical forests at La Selva Biological Station, Costa Rica. We measured an array of soil nutrients including total nitrogen (total N), inorganic N (nitrate [NO3-] and ammonium [NH4+]), phosphate (PO4-), and sum of base cations (SBC; potassium, magnesium, and calcium). Shade in the forest understory did not preclude seedling growth correlations with soil nutrients. Irradiance was a significant predictor of growth in 52% of the species, inorganic N in 54% (NO3- in 32%; NH4+ in 34%), total N in 47%, SBC in 39%, and PO4- in 29%. Overall, growth was correlated with both irradiance and soil nutrients in 45% of species and with soil nutrients only in an additional 48%; rarely was irradiance alone correlated with growth. Contrary to expectations, the magnitudes of growth effects, assessed as the maximum growth response to significant resources for each species, were similar for irradiance and most soil nutrients. Among species whose growth correlated with soil nutrients, the rank importance of nutrient effects was SBC, followed by N (total N, NO3-, and/or NH4+) and PO4-. Species' growth responsiveness (i.e., magnitudes of effect) to irradiance and soil nutrients was negatively correlated with species' shade tolerance (survival under 1% full sun). In this broad survey of species and resources, the nearly ubiquitous effects of soil nutrients on seedling growth challenge the idea that soil nutrients are less

Carbon storage in coarse and fine fractions of Pacific Northwest old-growth forest soils.

Treesearch

P.S. Homann; S.M. Remillard; M.E. Harmon; B.T. Bormann

2004-01-01

Many assessments of soil C have been restricted to the 2-mm fractions of forest mineral soils. Our objective was to determine the importance of the >2mm fraction to whole-soil C pools in Pacific Northwest old-growth coniferous forests. Seventy-nine pedons in 18 western Washington and Oregon forests were...

What is this thing called growth?

Treesearch

Adrian M. Gilbert

1954-01-01

What is this thing called "growth"? We foresters are constantly thinking in terms of growth. We use growth data to evaluate a forest property. We use them to determine how much we can cut. We use them to weigh the results of a type of cutting.

Optimal regeneration planning for old-growth forest: addressing scientific uncertainty in endangered species recovery through adaptive management

USGS Publications Warehouse

Moore, C.T.; Conroy, M.J.

2006-01-01

Stochastic and structural uncertainties about forest dynamics present challenges in the management of ephemeral habitat conditions for endangered forest species. Maintaining critical foraging and breeding habitat for the endangered red-cockaded woodpecker (Picoides borealis) requires an uninterrupted supply of old-growth forest. We constructed and optimized a dynamic forest growth model for the Piedmont National Wildlife Refuge (Georgia, USA) with the objective of perpetuating a maximum stream of old-growth forest habitat. Our model accommodates stochastic disturbances and hardwood succession rates, and uncertainty about model structure. We produced a regeneration policy that was indexed by current forest state and by current weight of evidence among alternative model forms. We used adaptive stochastic dynamic programming, which anticipates that model probabilities, as well as forest states, may change through time, with consequent evolution of the optimal decision for any given forest state. In light of considerable uncertainty about forest dynamics, we analyzed a set of competing models incorporating extreme, but plausible, parameter values. Under any of these models, forest silviculture practices currently recommended for the creation of woodpecker habitat are suboptimal. We endorse fully adaptive approaches to the management of endangered species habitats in which predictive modeling, monitoring, and assessment are tightly linked.

Predicting impacts of future human population growth and development on occupancy rates of forest-dependent birds

USGS Publications Warehouse

Brown, Michelle L.; Donovan, Therese; Schwenk, W. Scott; Theobald, David M.

2014-01-01

Forest loss and fragmentation are among the largest threats to forest-dwelling wildlife species today, and projected increases in human population growth are expected to increase these threats in the next century. We combined spatially-explicit growth models with wildlife distribution models to predict the effects of human development on 5 forest-dependent bird species in Vermont, New Hampshire, and Massachusetts, USA. We used single-species occupancy models to derive the probability of occupancy for each species across the study area in the years 2000 and 2050. Over half a million new housing units were predicted to be added to the landscape. The maximum change in housing density was nearly 30 houses per hectare; however, 30% of the towns in the study area were projected to add less than 1 housing unit per hectare. In the face of predicted human growth, the overall occupancy of each species decreased by as much as 38% (ranging from 19% to 38% declines in the worst-case scenario) in the year 2050. These declines were greater outside of protected areas than within protected lands. Ninety-seven percent of towns experienced some decline in species occupancy within their borders, highlighting the value of spatially-explicit models. The mean decrease in occupancy probability within towns ranged from 3% for hairy woodpecker to 8% for ovenbird and hermit thrush. Reductions in occupancy probability occurred on the perimeters of cities and towns where exurban development is predicted to increase in the study area. This spatial approach to wildlife planning provides data to evaluate trade-offs between development scenarios and forest-dependent wildlife species.

No growth stimulation of Canada’s boreal forest under half-century of combined warming and CO2 fertilization

PubMed Central

Girardin, Martin P.; Hogg, Edward H.; Kurz, Werner; Zimmermann, Niklaus E.; Metsaranta, Juha M.; de Jong, Rogier; Frank, David C.; Esper, Jan; Büntgen, Ulf; Guo, Xiao Jing; Bhatti, Jagtar

2016-01-01

Considerable evidence exists that current global temperatures are higher than at any time during the past millennium. However, the long-term impacts of rising temperatures and associated shifts in the hydrological cycle on the productivity of ecosystems remain poorly understood for mid to high northern latitudes. Here, we quantify species-specific spatiotemporal variability in terrestrial aboveground biomass stem growth across Canada’s boreal forests from 1950 to the present. We use 873 newly developed tree-ring chronologies from Canada’s National Forest Inventory, representing an unprecedented degree of sampling standardization for a large-scale dendrochronological study. We find significant regional- and species-related trends in growth, but the positive and negative trends compensate each other to yield no strong overall trend in forest growth when averaged across the Canadian boreal forest. The spatial patterns of growth trends identified in our analysis were to some extent coherent with trends estimated by remote sensing, but there are wide areas where remote-sensing information did not match the forest growth trends. Quantifications of tree growth variability as a function of climate factors and atmospheric CO2 concentration reveal strong negative temperature and positive moisture controls on spatial patterns of tree growth rates, emphasizing the ecological sensitivity to regime shifts in the hydrological cycle. An enhanced dependence of forest growth on soil moisture during the late-20th century coincides with a rapid rise in summer temperatures and occurs despite potential compensating effects from increased atmospheric CO2 concentration. PMID:27956624

Attaining the canopy in dry and moist tropical forests: strong differences in tree growth trajectories reflect variation in growing conditions

PubMed Central

Zuidema, Pieter A.; Martínez-Ramos, Miguel

2009-01-01

Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees—those that have not attained the canopy—are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests. Electronic supplementary material The online version of this article (doi:10.1007/s

ABOVE- AND BELOWGROUND CONTROLS ON FOREST TREE GROWTH, MORTALITY AND SPATIAL PATTERN

EPA Science Inventory

We investigated the relative importance of above- and belowground competition in controlling growth, mortality and spatial patterns of trees in a nitrogen-limited, old-growth forest in western Oregon. To assess the effects of competition for light, we applied a spatially-explici...

An Old-Growth Definition for Dry and Dry-Mesic Oak-Pine Forests.

Treesearch

David L. White; F. Thomas Lloyd

1998-01-01

Dry and dry-mesic oak-pine forests are widely distributed from New Jersey to Texas, but representative old-growth stands are rare. Historical accounts of composition, along with information from existing old-growth stands, were used to characterize this type. Shortleaf pine and white oak were the most widely distributed trees across all old-growth stands. Shortleaf was...

The AFIS tree growth model for updating annual forest inventories in Minnesota

Treesearch

Margaret R. Holdaway

2000-01-01

As the Forest Service moves towards annual inventories, states may use model predictions of growth to update unmeasured plots. A tree growth model (AFIS) based on the scaled Weibull function and using the average-adjusted model form is presented. Annual diameter growth for four species was modeled using undisturbed plots from Minnesota's Aspen-Birch and Northern...

Spatial models reveal the microclimatic buffering capacity of old-growth forests

PubMed Central

Frey, Sarah J. K.; Hadley, Adam S.; Johnson, Sherri L.; Schulze, Mark; Jones, Julia A.; Betts, Matthew G.

2016-01-01

Climate change is predicted to cause widespread declines in biodiversity, but these predictions are derived from coarse-resolution climate models applied at global scales. Such models lack the capacity to incorporate microclimate variability, which is critical to biodiversity microrefugia. In forested montane regions, microclimate is thought to be influenced by combined effects of elevation, microtopography, and vegetation, but their relative effects at fine spatial scales are poorly known. We used boosted regression trees to model the spatial distribution of fine-scale, under-canopy air temperatures in mountainous terrain. Spatial models predicted observed independent test data well (r = 0.87). As expected, elevation strongly predicted temperatures, but vegetation and microtopography also exerted critical effects. Old-growth vegetation characteristics, measured using LiDAR (light detection and ranging), appeared to have an insulating effect; maximum spring monthly temperatures decreased by 2.5°C across the observed gradient in old-growth structure. These cooling effects across a gradient in forest structure are of similar magnitude to 50-year forecasts of the Intergovernmental Panel on Climate Change and therefore have the potential to mitigate climate warming at local scales. Management strategies to conserve old-growth characteristics and to curb current rates of primary forest loss could maintain microrefugia, enhancing biodiversity persistence in mountainous systems under climate warming. PMID:27152339

Spatial models reveal the microclimatic buffering capacity of old-growth forests.

PubMed

Frey, Sarah J K; Hadley, Adam S; Johnson, Sherri L; Schulze, Mark; Jones, Julia A; Betts, Matthew G

2016-04-01

Climate change is predicted to cause widespread declines in biodiversity, but these predictions are derived from coarse-resolution climate models applied at global scales. Such models lack the capacity to incorporate microclimate variability, which is critical to biodiversity microrefugia. In forested montane regions, microclimate is thought to be influenced by combined effects of elevation, microtopography, and vegetation, but their relative effects at fine spatial scales are poorly known. We used boosted regression trees to model the spatial distribution of fine-scale, under-canopy air temperatures in mountainous terrain. Spatial models predicted observed independent test data well (r = 0.87). As expected, elevation strongly predicted temperatures, but vegetation and microtopography also exerted critical effects. Old-growth vegetation characteristics, measured using LiDAR (light detection and ranging), appeared to have an insulating effect; maximum spring monthly temperatures decreased by 2.5°C across the observed gradient in old-growth structure. These cooling effects across a gradient in forest structure are of similar magnitude to 50-year forecasts of the Intergovernmental Panel on Climate Change and therefore have the potential to mitigate climate warming at local scales. Management strategies to conserve old-growth characteristics and to curb current rates of primary forest loss could maintain microrefugia, enhancing biodiversity persistence in mountainous systems under climate warming.

The impact of atmospheric deposition and climate on forest growth in Europe using two empirical modelling approaches

NASA Astrophysics Data System (ADS)

Dobbertin, M.; Solberg, S.; Laubhann, D.; Sterba, H.; Reinds, G. J.; de Vries, W.

2009-04-01

Most recent studies show increasing forest growth in central Europe, rather than a decline as was expected due to negative effects of air pollution. While nitrogen deposition, increasing temperature and change in forest management are discussed as possible causes, quantification of the various environmental factors has rarely been undertaken. In our study, we used data from several hundreds of intensive monitoring plots from the ICP Forests network in Europe, ranging from northern Finland to Spain and southern Italy. Five-year growth data for the period 1994-1999 were available from roughly 650 plots to examine the influence of environmental factors on forest growth. Evaluations focused on the influence of nitrogen, sulphur and acid deposition, temperature, precipitation and drought. Concerning the latter meteorological variables we used the deviation from the long-term (30 years) mean. The study included the main tree species common beech (Fagus sylvatica), sessile or pedunculate oak (Quercus petraea and Q. robur), Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). Two very different approaches were used. In the first approach an individual tree-based regression model was applied (Laubhahn et al., 2009), while in the second approach a stand-based model was applied (Solberg et al., 2009). The individual tree-based model had measured basal area increment of each individual tree as a growth response variable and tree size (diameter at breast height), tree competition (basal area of larger trees and stand density index), site factors (e.g. soil C/N ratio, temperature), and environmental factors (e.g. temperature change compared to long-term average, nitrogen and sulphur deposition) as influencing parameters. In the stand-growth model, stem volume increment was used as the growth response variable, after filtering out the expected growth. Expected growth was modelled as a function of site productivity, stand age and a stand density index. Relative volume

Interspecific variation in growth responses to tree size, competition and climate of western Canadian boreal mixed forests.

PubMed

Jiang, Xinyu; Huang, Jian-Guo; Cheng, Jiong; Dawson, Andria; Stadt, Kenneth J; Comeau, Philip G; Chen, Han Y H

2018-08-01

Tree growth of boreal forest plays an important role on global carbon (C) cycle, while tree growth in the western Canadian boreal mixed forests has been predicted to be negatively affected by regional drought. Individual tree growth can be controlled by many factors, such as competition, climate, tree size and age. However, information about contributions of different factors to tree growth is still limited in this region. In order to address this uncertainty, tree rings of two dominant tree species, trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench.) Voss), were sampled from boreal mixed forest stands distributed across Alberta, Canada. Tree growth rates over different time intervals (10years interval, 1998-2007; 20years interval, 1988-2007; 30years interval, 1978-2007) were calculated to study the effects of different factors (tree size, competition, climate, and age) on tree growth. Results indicated that tree growth of two species were both primarily affected by competition or tree size, while climatic indices showed less effects on tree growth. Growth of trembling aspen was significantly affected by inter- and intraspecific competition, while growth of white spruce was primarily influenced by tree size, followed by competition. Positive relationship was found between growth of white spruce and competition index of coniferous group, suggesting an intraspecific mutualism mechanism within coniferous group. Our results further suggested that competition driven succession was the primary process of forest composition shift in the western Canadian boreal mixed forest. Although drought stress increased tree mortality, decline of stem density under climate change released competition stress of surviving trees, which in turn sustained growth of surviving trees. Therefore, climatic indices showed fewer effects on growth of dominant tree species compared to other factors in our study. Copyright © 2018 Elsevier B.V. All rights reserved.

Forest biomass carbon sinks in East Asia, with special reference to the relative contributions of forest expansion and forest growth.

PubMed

Fang, Jingyun; Guo, Zhaodi; Hu, Huifeng; Kato, Tomomichi; Muraoka, Hiroyuki; Son, Yowhan

2014-06-01

Forests play an important role in regional and global carbon (C) cycles. With extensive afforestation and reforestation efforts over the last several decades, forests in East Asia have largely expanded, but the dynamics of their C stocks have not been fully assessed. We estimated biomass C stocks of the forests in all five East Asian countries (China, Japan, North Korea, South Korea, and Mongolia) between the 1970s and the 2000s, using the biomass expansion factor method and forest inventory data. Forest area and biomass C density in the whole region increased from 179.78 × 10(6) ha and 38.6 Mg C ha(-1) in the 1970s to 196.65 × 10(6) ha and 45.5 Mg C ha(-1) in the 2000s, respectively. The C stock increased from 6.9 Pg C to 8.9 Pg C, with an averaged sequestration rate of 66.9 Tg C yr(-1). Among the five countries, China and Japan were two major contributors to the total region's forest C sink, with respective contributions of 71.1% and 32.9%. In China, the areal expansion of forest land was a larger contributor to C sinks than increased biomass density for all forests (60.0% vs. 40.0%) and for planted forests (58.1% vs. 41.9%), while the latter contributed more than the former for natural forests (87.0% vs. 13.0%). In Japan, increased biomass density dominated the C sink for all (101.5%), planted (91.1%), and natural (123.8%) forests. Forests in South Korea also acted as a C sink, contributing 9.4% of the total region's sink because of increased forest growth (98.6%). Compared to these countries, the reduction in forest land in both North Korea and Mongolia caused a C loss at an average rate of 9.0 Tg C yr(-1), equal to 13.4% of the total region's C sink. Over the last four decades, the biomass C sequestration by East Asia's forests offset 5.8% of its contemporary fossil-fuel CO2 emissions. © 2014 John Wiley & Sons Ltd.

Diameter growth of trees in an uneven-aged oak forest in the Missouri Ozarks

Treesearch

Edward F. Loewenstein; Paul S. Johnson; Harold E. Garrett

1997-01-01

We tested the efficacy of even-aged stand tables for predicting diameter growth of trees in uneven-aged oak stands. The study was based on the age- and diameter-structure of the Pioneer Forest, a 156,000-acre, privately owned oak forest in the Ozark Highlands of Missouri. The forest has been managed by single-tree selection since 1954.

Quantifying Forest Soil Physical Variables Potentially Important for Site Growth Analyses

Treesearch

John S. Kush; Douglas G. Pitt; Phillip J. Craul; William D. Boyer

2004-01-01

Accurate mean plot values of forest soil factors are required for use as independent variables in site-growth analyses. Adequate accuracy is often difficult to attain because soils are inherently widely variable. Estimates of the variability of appropriate soil factors influencing growth can be used to determine the sampling intensity required to secure accurate mean...

Forest canopy growth dynamic modeling based on remote sensing prodcuts and meteorological data in Daxing'anling of Northeast China

NASA Astrophysics Data System (ADS)

Wu, Qiaoli; Song, Jinling; Wang, Jindi; Xiao, Zhiqiang

2014-11-01

Leaf Area Index (LAI) is an important biophysical variable for vegetation. Compared with vegetation indexes like NDVI and EVI, LAI is more capable of monitoring forest canopy growth quantitatively. GLASS LAI is a spatially complete and temporally continuous product derived from AVHRR and MODIS reflectance data. In this paper, we present the approach to build dynamic LAI growth models for young and mature Larix gmelinii forest in north Daxing'anling in Inner Mongolia of China using the Dynamic Harmonic Regression (DHR) model and Double Logistic (D-L) model respectively, based on the time series extracted from multi-temporal GLASS LAI data. Meanwhile we used the dynamic threshold method to attract the key phenological phases of Larix gmelinii forest from the simulated time series. Then, through the relationship analysis between phenological phases and the meteorological factors, we found that the annual peak LAI and the annual maximum temperature have a good correlation coefficient. The results indicate this forest canopy growth dynamic model to be very effective in predicting forest canopy LAI growth and extracting forest canopy LAI growth dynamic.

Dynamic anthropogenic edge effects on the distribution and diversity of fungi in fragmented old-growth forests.

PubMed

Ruete, Alejandro; Snäll, Tord; Jönsson, Mari

2016-07-01

Diversity patterns and dynamics at forest edges are not well understood. We disentangle the relative importance of edge-effect variables on spatio-temporal patterns in species richness and occupancy of deadwood-dwelling fungi in fragmented old-growth forests. We related richness and log occupancy by 10 old-growth forest indicator fungi and by two common fungi to log conditions in natural and anthropogenic edge habitats of 31 old-growth Picea abies forest stands in central Sweden. We compared edge-to-interior gradients (100 m) to the forest interior (beyond 100 m), and we analyzed stand-level changes after 10 yr. Both richness and occupancy of logs by indicator species was negatively related to adjacent young clear-cut edges, but this effect decreased with increasing clear-cut age. The occupancy of logs by indicator species also increased with increasing distance to the natural edges. In contrast, the occupancy of logs by common species was positively related or unrelated to distance to clear-cut edges regardless of the edge age, and this was partly explained by fungal specificity to substrate quality. Stand-level mean richness and mean occupancy of logs did not change for indicator or common species over a decade. By illustrating the importance of spatial and temporal dimensions of edge effects, we extend the general understanding of the distribution and diversity of substrate-confined fungi in fragmented old-growth forests. Our results highlight the importance of longer forest rotation times adjacent to small protected areas and forest set-asides, where it may take more than 50 yr for indicator species richness levels to recover to occupancy levels observed in the forest interior. Also, non-simultaneous clear-cutting of surrounding productive forests in a way that reduces the edge effect over time (i.e., dynamic buffers) may increase the effective core area of small forest set-asides and improve their performance on protecting species of special concern for

Spider (Arachnida, Araneae) diversity in secondary and old-growth southern Atlantic forests of Paraná state, Brazil.

PubMed

Raub, Florian; Höfer, Hubert; Scheuermann, Ludger

2017-07-01

The data presented here have been collected in the southern part of the Atlantic Forest (Mata Atlântica) in the state of Paraná, Brazil within a bilateral scientific project (SOLOBIOMA). The project aimed to assess the quality of secondary forests of different regeneration stages in comparison with old-growth forests with regard to diversity of soil animals and related functions. The Atlantic Forest is a hotspot of biological diversity with an exceptionally high degree of endemic species, extending over a range of 3,500 km along the coast of Brazil. The anthropogenic pressure in the region is very high with three of the biggest cities of Brazil (São Paulo, Rio de Janeiro, and Curitiba) lying in its extension. An evaluation of the value of secondary forests for biodiversity conservation is becoming more and more important due to the complete disappearance of primary forests. In 2005, we sampled spiders in 12 sites of three successional stages (5-8, 10-15, 35-50 yr old, three replicates of each forest stage) and old-growth forests (> 100 yr untouched, also three replicates). All sites were inside a private nature reserve (Rio Cachoeira Nature Reserve). We repeated the sampling design and procedure in 2007 in a second private reserve (Itaqui Nature Reserve). The two nature reserves are within about 25 km of each other within a well preserved region of the Mata Atlântica, where the matrix of the landscape mosaic is still forest. A widely accepted standard protocol was used in a replicated sampling design to apply statistical analyses to the resulting data set and allow for comparison with other studies in Brazil. Spiders were sorted to family level and counted; the adult spiders further identified to species if possible or classified as morphospecies with the help of several spider specialists. © 2017 by the Ecological Society of America.

Thirty-two years of change in an old-growth Ohio beech-maple forest.

PubMed

Runkle, James R

2013-05-01

Old-growth forests dominated by understory-tolerant tree species are among forest types most likely to be in equilibrium. However, documentation of the degree to which they are in equilibrium over decades-long time periods is lacking. Changes in climate, pathogens, and land use all are likely to impact stand characteristics and species composition, even in these forests. Here, 32 years of vegetation changes in an old-growth beech (Fagus grandifolia)-sugar maple (Acer saccharum) forest in Hueston Woods, southwest Ohio, USA, are summarized. These changes involve canopy composition and structure, turnover in snags, and development of vegetation in treefall gaps. Stand basal area and canopy density have changed little in 32 years. However, beech has decreased in canopy importance (49% to 32%) while sugar maple has increased (32% to 47%). Annual mortality was about 1.3% throughout the study period. Mortality rates increased with stem size, but the fraction of larger stems increased due to ingrowth from smaller size classes. Beech was represented by more very large stems than small canopy stems: over time, death of those larger stems with inadequate replacement has caused the decrease in beech importance. Sugar maple was represented by more small canopy stems whose growth has increased its importance. The changes in beech and sugar maple relative importance are hypothesized to be due to forest fragmentation mostly from the early 1800s with some possible additional effects associated with the formation of the state park. Snag densities (12-16 snags/ha) and formation rates (1-3 snags.ha(-1).yr(-1)) remained consistent. The treefall gaps previously studied are closing, with a few, large stems remaining. Death of gap border trees occurs consistently enough to favor species able to combine growth in gaps and survival in the understory.

Implementing a national process for estimating growth, removals, and mortality at the Pacific Northwest’s Forest Inventory and Analysis’s Region: modeling diameter growth

Treesearch

Olaf. Kuegler

2015-01-01

The Pacific Northwest Research Station’s Forest Inventory and Analysis Unit began remeasurement of permanently located FIA plots under the annualized design in 2011. With remeasurement has come the need to implement the national FIA system for compiling estimates of forest growth, removals, and mortality. The national system requires regional diameter-growth models to...

Large Impacts of Climatic Warming on Growth of Boreal Forests since 1960

PubMed Central

Kauppi, Pekka E.; Posch, Maximilian; Pirinen, Pentti

2014-01-01

Boreal forests are sensitive to climatic warming, because low temperatures hold back ecosystem processes, such as the mobilization of nitrogen in soils. A greening of the boreal landscape has been observed using remote sensing, and the seasonal amplitude of CO2 in the northern hemisphere has increased, indicating warming effects on ecosystem productivity. However, field observations on responses of ecosystem productivity have been lacking on a large sub-biome scale. Here we report a significant increase in the annual growth of boreal forests in Finland in response to climatic warming, especially since 1990. This finding is obtained by linking meteorological records and forest inventory data on an area between 60° and 70° northern latitude. An additional increase in growth has occurred in response to changes in other drivers, such as forest management, nitrogen deposition and/or CO2 concentration. A similar warming impact can be expected in the entire boreal zone, where warming takes place. Given the large size of the boreal biome – more than ten million km2– important climate feedbacks are at stake, such as the future carbon balance, transpiration and albedo. PMID:25383552

Large impacts of climatic warming on growth of boreal forests since 1960.

PubMed

Kauppi, Pekka E; Posch, Maximilian; Pirinen, Pentti

2014-01-01

Boreal forests are sensitive to climatic warming, because low temperatures hold back ecosystem processes, such as the mobilization of nitrogen in soils. A greening of the boreal landscape has been observed using remote sensing, and the seasonal amplitude of CO2 in the northern hemisphere has increased, indicating warming effects on ecosystem productivity. However, field observations on responses of ecosystem productivity have been lacking on a large sub-biome scale. Here we report a significant increase in the annual growth of boreal forests in Finland in response to climatic warming, especially since 1990. This finding is obtained by linking meteorological records and forest inventory data on an area between 60° and 70° northern latitude. An additional increase in growth has occurred in response to changes in other drivers, such as forest management, nitrogen deposition and/or CO2 concentration. A similar warming impact can be expected in the entire boreal zone, where warming takes place. Given the large size of the boreal biome - more than ten million km2- important climate feedbacks are at stake, such as the future carbon balance, transpiration and albedo.

Dampening effects of long-term experimental drought on growth and mortality rates of a Holm oak forest.

PubMed

Barbeta, Adrià; Ogaya, Romà; Peñuelas, Josep

2013-10-01

evaluate the effect of long-term (13 years) experimental drought on growth and mortality rates of three forest Mediterranean species, and their response to the different intensities and durations of natural drought. We provide evidence for species-specific responses to drought, what may eventually lead to a partial community shift favoring the more drought-resistant species. However, we also report a dampening of the treatment effect on the two drought-sensitive species, which may indicate a potential adaptation to drier conditions at the ecosystem or population level. These results are thus relevant to account for the stabilizing processes that would alter the initial response of ecosystem to drought through changes in plant physiology, morphology, and demography compensation. © 2013 John Wiley & Sons Ltd.

Tree species and soil nutrient profiles in old-growth forests of the Oregon Coast Range

USGS Publications Warehouse

Cross, Alison; Perakis, Steven S.

2011-01-01

Old-growth forests of the Pacific Northwest provide a unique opportunity to examine tree species – soil relationships in ecosystems that have developed without significant human disturbance. We characterized foliage, forest floor, and mineral soil nutrients associated with four canopy tree species (Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), western redcedar (Thuja plicata Donn ex D. Don), and bigleaf maple (Acer macrophyllum Pursh)) in eight old-growth forests of the Oregon Coast Range. The greatest forest floor accumulations of C, N, P, Ca, Mg, and K occurred under Douglas-fir, primarily due to greater forest floor mass. In mineral soil, western hemlock exhibited significantly lower Ca concentration and sum of cations (Ca + Mg + K) than bigleaf maple, with intermediate values for Douglas-fir and western redcedar. Bigleaf maple explained most species-based differences in foliar nutrients, displaying high concentrations of N, P, Ca, Mg, and K. Foliar P and N:P variations largely reflected soil P variation across sites. The four tree species that we examined exhibited a number of individualistic effects on soil nutrient levels that contribute to biogeochemical heterogeneity in these ecosystems. Where fire suppression and long-term succession favor dominance by highly shade-tolerant western hemlock, our results suggest a potential for declines in both soil Ca availability and soil biogeochemical heterogeneity in old-growth forests.

Responses of Tree Growths to Tree Size, Competition, and Topographic Conditions in Sierra Nevada Forests Using Bi-temporal Airborne LiDAR Data

NASA Astrophysics Data System (ADS)

Ma, Q.; Su, Y.; Tao, S.; Guo, Q.

2016-12-01

Trees in the Sierra Nevada (SN) forests are experiencing rapid changes due to human disturbances and climatic changes. An improved monitoring of tree growth and understanding of how tree growth responses to different impact factors, such as tree competition, forest density, topographic and hydrologic conditions, are urgently needed in tree growth modeling. Traditional tree growth modeling mainly relied on field survey, which was highly time-consuming and labor-intensive. Airborne Light detection and ranging System (ALS) is increasingly used in forest survey, due to its high efficiency and accuracy in three-dimensional tree structure delineation and terrain characterization. This study successfully detected individual tree growth in height (ΔH), crown area (ΔA), and crown volume (ΔV) over a five-year period (2007-2012) using bi-temporal ALS data in two conifer forest areas in SN. We further analyzed their responses to original tree size, competition indices, forest structure indices, and topographic environmental parameters at individual tree and forest stand scales. Our results indicated ΔH was strongly sensitive to topographic wetness index; whereas ΔA and ΔV were highly responsive to forest density and original tree sizes. These ALS based findings in ΔH were consistent with field measurements. Our study demonstrated the promising potential of using bi-temporal ALS data in forest growth measurements and analysis. A more comprehensive study over a longer temporal period and a wider range of forest stands would give better insights into tree growth in the SN, and provide useful guides for forest growth monitoring, modeling, and management.

Forest Fire Prevention Programs and Their Evaluation In U.S. Forest Service Region 8

Treesearch

G. Richard Wetherill

1982-01-01

A telephone survey of all national forest ranger districts in Region 8 obtained data describing the status of forest fire prevention program evaluation. Out of the 396 programs being conducted on the 105 districts in the South, only one program had undergone any sort of systematic evaluation. Survey data indicate that ranger district prevention personnel are aware of...

Housing growth, forests, and public lands in Northern Wisconsin form 1940 to 2000

Treesearch

Roger B. Hammer; Susan I. Stewart; Todd J. Hawbaker; Volker C. Radeloff

2009-01-01

Rural, forested areas throughout the United States are experiencing strong housing growth with potentially detrimental impacts on the environment. In this paper, we quantify housing growth in Northern Wisconsin over the last sixty years to determine if growth rates were higher near public lands, which may represent an important recreational amenity. We used data from...

Interim definitions for old growth Douglas-fir and mixed-conifer forests in the Pacific Northwest and California.

Treesearch

J.F. Franklin; F. Hall; W. Laudenslayer; C. Maser; J. Nunan; J. Poppino; C.J. Ralph; T. Spies

1986-01-01

Interim definitions of old-growth forests are provided to guide efforts in land-management planning until comprehensive definitions based on research that is currently underway can be formulated. The basic criteria for identifying old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and mixed-conifer forests in western Washington and...

Formulating a stand-growth model for mathematical programming problems in Appalachian forests

Treesearch

Gary W. Miller; Jay Sullivan

1993-01-01

Some growth and yield simulators applicable to central hardwood forests can be formulated for use in mathematical programming models that are designed to optimize multi-stand, multi-resource management problems. Once in the required format, growth equations serve as model constraints, defining the dynamics of stand development brought about by harvesting decisions. In...

Integrating carbon nanotube forests into polysilicon MEMS: Growth kinetics, mechanisms, and adhesion

DOE PAGES

Ubnoske, Stephen M.; Radauscher, Erich J.; Meshot, Eric R.; ...

2016-11-19

The growth of carbon nanotubes (CNTs) on polycrystalline silicon substrates was studied to improve the design of CNT field emission sources for microelectromechanical systems (MEMS) applications and vacuum microelectronic devices (VMDs). Microwave plasma-enhanced chemical vapor deposition (PECVD) was used for CNT growth, resulting in CNTs that incorporate the catalyst particle at their base. The kinetics of CNT growth on polysilicon were compared to growth on Si (100) using the model of Deal and Grove, finding activation energies of 1.61 and 1.54 eV for the nucleation phase of growth and 1.90 and 3.69 eV for the diffusion-limited phase on Si (100)more » and polysilicon, respectively. Diffusivity values for growth on polysilicon were notably lower than the corresponding values on Si (100) and the growth process became diffusion-limited earlier. Evidence favors a surface diffusion growth mechanism involving diffusion of carbon precursor species along the length of the CNT forest to the catalyst at the base. Explanations for the differences in activation energies and diffusivities were elucidated by SEM analysis of the catalyst nanoparticle arrays and through wide-angle X-ray scattering (WAXS) of CNT forests. As a result, methods are presented to improve adhesion of CNT films during operation as field emitters, resulting in a 2.5× improvement.« less

Integrating carbon nanotube forests into polysilicon MEMS: Growth kinetics, mechanisms, and adhesion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ubnoske, Stephen M.; Radauscher, Erich J.; Meshot, Eric R.

The growth of carbon nanotubes (CNTs) on polycrystalline silicon substrates was studied to improve the design of CNT field emission sources for microelectromechanical systems (MEMS) applications and vacuum microelectronic devices (VMDs). Microwave plasma-enhanced chemical vapor deposition (PECVD) was used for CNT growth, resulting in CNTs that incorporate the catalyst particle at their base. The kinetics of CNT growth on polysilicon were compared to growth on Si (100) using the model of Deal and Grove, finding activation energies of 1.61 and 1.54 eV for the nucleation phase of growth and 1.90 and 3.69 eV for the diffusion-limited phase on Si (100)more » and polysilicon, respectively. Diffusivity values for growth on polysilicon were notably lower than the corresponding values on Si (100) and the growth process became diffusion-limited earlier. Evidence favors a surface diffusion growth mechanism involving diffusion of carbon precursor species along the length of the CNT forest to the catalyst at the base. Explanations for the differences in activation energies and diffusivities were elucidated by SEM analysis of the catalyst nanoparticle arrays and through wide-angle X-ray scattering (WAXS) of CNT forests. As a result, methods are presented to improve adhesion of CNT films during operation as field emitters, resulting in a 2.5× improvement.« less

Loblolly pine growth and soil nutrient stocks eight years after forest slash incorporation

Treesearch

Felipe G. Sanchez; Emily A. Carter; Zakiya H. Leggett

2009-01-01

Incorporation of forest slash during stand establishment is proposed as a means of increasing soil carbon and nutrient stocks. If effective, the increased soil carbon and nutrient status may result in increased aboveground tree growth. Eight years after study installation, the impact of forest slash incorporation into the soil on soil carbon and nutrient stocks, foliar...

Modeling Forest Biomass and Growth: Coupling Long-Term Inventory and Lidar Data

NASA Technical Reports Server (NTRS)

Babcock, Chad; Finley, Andrew O.; Cook, Bruce D.; Weiskittel, Andrew; Woodall, Christopher W.

2016-01-01

Combining spatially-explicit long-term forest inventory and remotely sensed information from Light Detection and Ranging (LiDAR) datasets through statistical models can be a powerful tool for predicting and mapping above-ground biomass (AGB) at a range of geographic scales. We present and examine a novel modeling approach to improve prediction of AGB and estimate AGB growth using LiDAR data. The proposed model accommodates temporal misalignment between field measurements and remotely sensed data-a problem pervasive in such settings-by including multiple time-indexed measurements at plot locations to estimate AGB growth. We pursue a Bayesian modeling framework that allows for appropriately complex parameter associations and uncertainty propagation through to prediction. Specifically, we identify a space-varying coefficients model to predict and map AGB and its associated growth simultaneously. The proposed model is assessed using LiDAR data acquired from NASA Goddard's LiDAR, Hyper-spectral & Thermal imager and field inventory data from the Penobscot Experimental Forest in Bradley, Maine. The proposed model outperformed the time-invariant counterpart models in predictive performance as indicated by a substantial reduction in root mean squared error. The proposed model adequately accounts for temporal misalignment through the estimation of forest AGB growth and accommodates residual spatial dependence. Results from this analysis suggest that future AGB models informed using remotely sensed data, such as LiDAR, may be improved by adapting traditional modeling frameworks to account for temporal misalignment and spatial dependence using random effects.

Ecosystem and decomposer effects on litter dynamics along an old field to old-growth forest successional gradient

NASA Astrophysics Data System (ADS)

Mayer, Paul M.

2008-03-01

Identifying the biotic (e.g. decomposers, vegetation) and abiotic (e.g. temperature, moisture) mechanisms controlling litter decomposition is key to understanding ecosystem function, especially where variation in ecosystem structure due to successional processes may alter the strength of these mechanisms. To identify these controls and feedbacks, I measured mass loss and N flux in herbaceous, leaf, and wood litter along a successional gradient of ecosystem types (old field, transition forest, old-growth forest) while manipulating detritivore access to litter. Ecosystem type, litter type, and decomposers contributed directly and interactively to decomposition. Litter mass loss and N accumulation was higher while litter C:N remained lower in old-growth forests than in either old fields or transition forest. Old-growth forests influenced litter dynamics via microclimate (coolest and wettest) but also, apparently, through a decomposer community adapted to consuming the large standing stocks of leaf litter, as indicated by rapid leaf litter loss. In all ecosystem types, mass loss of herbaceous litter was greater than leaf litter which, in turn was greater than wood. However, net N loss from wood litter was faster than expected, suggesting localized N flux effects of wood litter. Restricting detritivore access to litter reduced litter mass loss and slowed the accumulation of N in litter, suggesting that macro-detritivores affect both physical and chemical characteristics of litter through selective grazing. These data suggest that the distinctive litter loss rates and efficient N cycling observed in old-growth forest ecosystems are not likely to be realized soon after old fields are restored to forested ecosystems.

Predicting long-term streamflow variability in moist eucalypt forests using forest growth models and a sapwood area index

NASA Astrophysics Data System (ADS)

Jaskierniak, D.; Kuczera, G.; Benyon, R.

2016-04-01

A major challenge in surface hydrology involves predicting streamflow in ungauged catchments with heterogeneous vegetation and spatiotemporally varying evapotranspiration (ET) rates. We present a top-down approach for quantifying the influence of broad-scale changes in forest structure on ET and hence streamflow. Across three catchments between 18 and 100 km2 in size and with regenerating Eucalyptus regnans and E. delegatensis forest, we demonstrate how variation in ET can be mapped in space and over time using LiDAR data and commonly available forest inventory data. The model scales plot-level sapwood area (SA) to the catchment-level using basal area (BA) and tree stocking density (N) estimates in forest growth models. The SA estimates over a 69 year regeneration period are used in a relationship between SA and vegetation induced streamflow loss (L) to predict annual streamflow (Q) with annual rainfall (P) estimates. Without calibrating P, BA, N, SA, and L to Q data, we predict annual Q with R2 between 0.68 and 0.75 and Nash Sutcliffe efficiency (NSE) between 0.44 and 0.48. To remove bias, the model was extended to allow for runoff carry-over into the following year as well as minor correction to rainfall bias, which produced R2 values between 0.72 and 0.79, and NSE between 0.70 and 0.79. The model under-predicts streamflow during drought periods as it lacks representation of ecohydrological processes that reduce L with either reduced growth rates or rainfall interception during drought. Refining the relationship between sapwood thickness and forest inventory variables is likely to further improve results.

Nutrient foraging strategies are associated with productivity and population growth in forest shrubs

PubMed Central

Stone, Bram W. G.; Faillace, Cara A.; Lafond, Jonathan J.; Baumgarten, Joni M.; Mozdzer, Thomas J.; Dighton, John; Meiners, Scott J.; Grabosky, Jason C.; Ehrenfeld, Joan G.

2017-01-01

Background and Aims Temperate deciduous forest understoreys are experiencing widespread changes in community composition, concurrent with increases in rates of nitrogen supply. These shifts in plant abundance may be driven by interspecific differences in nutrient foraging (i.e. conservative vs. acquisitive strategies) and, thus, adaptation to contemporary nutrient loading conditions. This study sought to determine if interspecific differences in nutrient foraging could help explain patterns of shrub success and decline in eastern North American forests. Methods Using plants grown in a common garden, fine root traits associated with nutrient foraging were measured for six shrub species. Traits included the mean and skewness of the root diameter distribution, specific root length (SRL), C:N ratio, root tissue density, arbuscular mycorrhizal colonization and foraging precision. Above- and below-ground productivity were also determined for the same plants, and population growth rates were estimated using data from a long-term study of community dynamics. Root traits were compared among species and associations among root traits, measures of productivity and rates of population growth were evaluated. Key Results Species fell into groups having thick or thin root forms, which correspond to conservative vs. acquisitive nutrient foraging strategies. Interspecific variation in root morphology and tissue construction correlated with measures of productivity and rates of cover expansion. Of the four species with acquisitive traits, three were introduced species that have become invasive in recent decades, and the fourth was a weedy native. In contrast, the two species with conservative traits were historically dominant shrubs that have declined in abundance in eastern North American forests. Conclusions In forest understoreys of eastern North America, elevated nutrient availability may impose a filter on species success in addition to above-ground processes such as herbivory

Discrimination between acute and chronic decline of Central European forests using map algebra of the growth condition and forest biomass fuzzy sets: A case study.

PubMed

Samec, Pavel; Caha, Jan; Zapletal, Miloš; Tuček, Pavel; Cudlín, Pavel; Kučera, Miloš

2017-12-01

Forest decline is either caused by damage or else by vulnerability due to unfavourable growth conditions or due to unnatural silvicultural systems. Here, we assess forest decline in the Czech Republic (Central Europe) using fuzzy functions, fuzzy sets and fuzzy rating of ecosystem properties over a 1×1km grid. The model was divided into fuzzy functions of the abiotic predictors of growth conditions (F pred including temperature, precipitation, acid deposition, soil data and relative site insolation) and forest biomass receptors (F rec including remote sensing data, density and volume of aboveground biomass, and surface humus chemical data). Fuzzy functions were designed at the limits of unfavourable, undetermined or favourable effects on the forest ecosystem health status. Fuzzy sets were distinguished through similarity in a particular membership of the properties at the limits of the forest status margins. Fuzzy rating was obtained from the least difference of F pred -F rec . Unfavourable F pred within unfavourable F rec indicated chronic damage, favourable F pred within unfavourable F rec indicated acute damage, and unfavourable F pred within favourable F rec indicated vulnerability. The model in the 1×1km grid was validated through spatial intersection with a point field of uniform forest stands. Favourable status was characterised by soil base saturation (BS)>50%, BCC/Al>1, C org >1%, MgO>6g/kg, and nitrogen deposition<1200mol(H + )/ha·year. Vulnerable forests had BS humus 46-60%, BCC/Al 9-20 and NDVI≈0.42. Chronic forest damage occurs in areas with low temperatures, high nitrogen deposition, and low soil BS and C org levels. In the Czech Republic, 10% of forests were considered non-damaged and 77% vulnerable, with damage considered acute in 7% of forests and chronic in 5%. The fuzzy model used suggests that improvement in forest health will depend on decreasing environmental load and restoration concordance between growth conditions and tree species

Fine Root Growth Phenology, Production, and Turnover in a Northern Hardwood Forest Ecosystem

Treesearch

Dudley J. Raynal

1994-01-01

A large part of the nutrient flux in deciduous forests is through fine root turnover, yet this process is seldom measured. As part of a nutrient cycling study, fine root dynamics were studied for two years at Huntington Forest in the Adirondack Mountain region of New York, USA. Root growth phenology was characterized using field rhizotrons, three methods were used to...

Plot size recommendations for biomass estimation in a midwestern old-growth forest

Treesearch

Martin A. Spetich; George R Parker

1998-01-01

The authors examine the relationship between disturbance regime and plot size for woody biomass estimation in a midwestern old-growth deciduous forest from 1926 to 1992. Analysis was done on the core 19.6 ac of a 50.1 ac forest in which every tree 4 in. d.b.h. and greater has been tagged and mapped since 1926. Five windows of time are compared—1926, 1976, 1981, 1986...

Multidecadal stability in tropical rain forest structure and dynamics across an old-growth landscape

PubMed Central

Clark, Deborah A.; Oberbauer, Steven F.; Kellner, James R.

2017-01-01

Have tropical rain forest landscapes changed directionally through recent decades? To answer this question requires tracking forest structure and dynamics through time and across within-forest environmental heterogeneity. While the impacts of major environmental gradients in soil nutrients, climate and topography on lowland tropical rain forest (TRF) structure and function have been extensively analyzed, the effects of the shorter environmental gradients typical of mesoscale TRF landscapes remain poorly understood. To evaluate multi-decadal performance of an old-growth TRF at the La Selva Biological Station, Costa Rica, we established 18 0.5-ha annually-censused forest inventory plots in a stratified-random design across major landscape edaphic gradients. Over the 17-year study period, there were moderate differences in stand dynamics and structure across these gradients but no detectable difference in woody productivity. We found large effects on forest structure and dynamics from the mega-Niño event at the outset of the study, with subdecadal recovery and subsequent stabilization. To extend the timeline to >40 years, we combined our findings with those from earlier studies at this site. While there were annual to multiannual variations in the structure and dynamics, particularly in relation to local disturbances and the mega-Niño event, at the longer temporal scale and broader spatial scale this landscape was remarkably stable. This stability contrasts notably with a current hypothesis of increasing biomass and dynamics of TRF, which we term the Bigger and Faster Hypothesis (B&FHo). We consider possible reasons for the contradiction and conclude that it is currently not possible to independently assess the vast majority of previously published B&FHo evidence due to restricted data access. PMID:28981502

Disturbance legacies and climate jointly drive tree growth and mortality in an intensively studied boreal forest.

PubMed

Bond-Lamberty, Ben; Rocha, Adrian V; Calvin, Katherine; Holmes, Bruce; Wang, Chuankuan; Goulden, Michael L

2014-01-01

Most North American forests are at some stage of post-disturbance regrowth, subject to a changing climate, and exhibit growth and mortality patterns that may not be closely coupled to annual environmental conditions. Distinguishing the possibly interacting effects of these processes is necessary to put short-term studies in a longer term context, and particularly important for the carbon-dense, fire-prone boreal forest. The goals of this study were to combine dendrochronological sampling, inventory records, and machine-learning algorithms to understand how tree growth and death have changed at one highly studied site (Northern Old Black Spruce, NOBS) in the central Canadian boreal forest. Over the 1999-2012 inventory period, mean tree diameter increased even as stand density and basal area declined significantly. Tree mortality averaged 1.4 ± 0.6% yr-(1), with most mortality occurring in medium-sized trees; new recruitment was minimal. There have been at least two, and probably three, significant influxes of new trees since stand initiation, but none in recent decades. A combined tree ring chronology constructed from sampling in 2001, 2004, and 2012 showed several periods of extreme growth depression, with increased mortality lagging depressed growth by ~5 years. Higher minimum and maximum air temperatures exerted a negative influence on tree growth, while precipitation and climate moisture index had a positive effect; both current- and previous-year data exerted significant effects. Models based on these variables explained 23-44% of the ring-width variability. We suggest that past climate extremes led to significant mortality still visible in the current forest structure, with decadal dynamics superimposed on slower patterns of fire and succession. These results have significant implications for our understanding of previous work at NOBS, the carbon sequestration capability of old-growth stands in a disturbance-prone landscape, and the sustainable management of

Disturbance, life history traits, and dynamics in an old-growth forest landscape of southeastern Europe.

PubMed

Nagel, Thomas A; Svoboda, Miroslav; Kobal, Milan

2014-06-01

Much of our understanding of natural forest dynamics in the temperate region of Europe is based on observational studies in old-growth remnants that have emphasized small-scale gap dynamics and equilibrium stand structure and composition. Relatively little attention has been given to the role of infrequent disturbance events in forest dynamics. In this study, we analyzed dendroecological data from four stands and three windthrow patches in an old-growth landscape in the Dinaric Mountains of Bosnia and Herzegovina to examine disturbance history, tree life history traits, and compositional dynamics. Over all stands, most decades during the past 340 years experienced less than 10% canopy loss, yet each stand showed evidence of periodic intermediate-severity disturbances that removed > 40% of the canopy, some of which were synchronized over the study area landscape. Analysis of radial growth patterns indicated several life history differences among the dominant canopy trees; beech was markedly older than fir, while growth patterns of dead and dying trees suggested that fir was able to tolerate longer periods of suppressed growth in shade. Maple had the fastest radial growth and accessed the canopy primarily through rapid early growth in canopy gaps, whereas most beech and fir experienced a period of suppressed growth prior to canopy accession. Peaks in disturbance were roughly linked to increased recruitment, but mainly of shade-tolerant beech and fir; less tolerant species (i.e., maple, ash, and elm) recruited successfully on some of the windthown sites where advance regeneration of beech and fir was less abundant. The results challenge the traditional notions of stability in temperate old-growth forests of Europe and highlight the nonequilibrial nature of canopy composition due to unique histories of disturbance and tree life history differences. These findings provide valuable information for developing natural disturbance-based silvicultural systems, as well as

Spatial and temporal variation in soil CO2 efflux in an old-growth neotropical rain forest, LA Selva, Costa Rica

Treesearch

Luitgard Schwendenmann; Edzo Veldkamp; Tania Brenes; Joseph J. O' Brien; Jens Mackensen

2003-01-01

Our objectives were to quantify and compare soil CO2, efflux of two doininant soil types in an old-growth neotropical rain forest in the Atlantic zone of Costa Rica, and to evaluate the control of environmental Factors on CO2, release. We measured soil CO2 efflux from eight permanent soil chamhers on...

Diameter growth performance of tree functional groups in Puerto Rican secondary tropical forests.

Treesearch

Patricia Adame; Maria Uriarte; Thomas Brandeis

2014-01-01

Aim of study: Understanding the factors that control tree growth in successional stands is particularly important for quantifying the carbon sequestration potential and timber yield of secondary tropical forests. Understanding the factors that control tree growth in successional stands is particularly important for quantifying the carbon sequestration potential and...

Evaluating climate variability and management impacts on carbon dynamics of a temperate forest using a variety of techniques

NASA Astrophysics Data System (ADS)

Arain, M. A.

2015-12-01

Climate variability, extreme weather events, forest age and management history impacts carbon sequestration in forest ecosystems. A variety of measurement techniques such as eddy covariance, dendrochronology, automatic soil CO2 chambers and remote sensing are employed fully understand forest carbon dynamics. Here, we present carbon flux measurements from 2003-2014 in a 76-year old managed temperate pine ((-Pinus strobus L.) forest, near Lake Erie in southern Ontario, Canada. Forest was partially thinned (30% tree harvested) in 1983 and 2012. The thinning in 2012 did not significantly impact carbon fluxes as post-thinning fluxes were within the range of inter-annual variability. Mean annual post-thinning (2012-2104) gross ecosystem productivity (GEP) measure by the eddy covariance technique was 1518 ± 78 g C m-2 year-1 as compared to pre-thinning (2003-2011) GEP of 1384 ± 121 g C m-2·year-1. Over the same period, mean post-thinning net ecosystem productivity (NEP) was 185 ± 75 g C m-2 year-1 as compared to post-thinning NEP of 180 ± 70 g C m-2 year-1, indicating that pre-thinning NEP was not significantly different than post-thinning NEP. Only post-thinning mean annual ecosystem respiration (Re; 1322 ± 54 g C m-2 year-1) was higher than pre-thinning Re (1195 ± 101 g C m-2 year-1). Soil CO2 efflux measurements showed similar trends. We also evaluated the impacts of climate variability and management regime on the full life cycle of the forest using annual radial tree-ring growths from 15 trees and compared them with historical climate (temperature and precipitation) data. While the annual growth rates displayed weak correlation with long-term climatic records, the growth was generally reduced during years with extreme drought (-36% of mean annual precipitation) and extreme temperature variability (±0.6 - 1.0°C). Overall, forest was more sensitive to management regime than climate variability. It showed higher growth stress during low light condition after

Stand density guides for predicting growth of forest tress of southwest Idaho

Treesearch

Douglas D. Basford; John Sloan; Joy Roberts

2010-01-01

This paper presents a method for estimating stand growth from stand density and average diameter in stands of pure and mixed species in Southwest Idaho. The methods are adapted from a model developed for Douglas-fir, ponderosa pine, and lodgepole pine on the Salmon National Forest. Growth data were derived from ponderosa pine increment cores taken from sample plots on...

Long-term forest resilience to climate change indicated by mortality, regeneration, and growth in semiarid southern Siberia.

PubMed

Xu, Chongyang; Liu, Hongyan; Anenkhonov, Oleg A; Korolyuk, Andrey Yu; Sandanov, Denis V; Balsanova, Larisa D; Naidanov, Bulat B; Wu, Xiuchen

2017-06-01

Several studies have documented that regional climate warming and the resulting increase in drought stress have triggered increased tree mortality in semiarid forests with unavoidable impacts on regional and global carbon sequestration. Although climate warming is projected to continue into the future, studies examining long-term resilience of semiarid forests against climate change are limited. In this study, long-term forest resilience was defined as the capacity of forest recruitment to compensate for losses from mortality. We observed an obvious change in long-term forest resilience along a local aridity gradient by reconstructing tree growth trend and disturbance history and investigating postdisturbance regeneration in semiarid forests in southern Siberia. In our study, with increased severity of local aridity, forests became vulnerable to drought stress, and regeneration first accelerated and then ceased. Radial growth of trees during 1900-2012 was also relatively stable on the moderately arid site. Furthermore, we found that smaller forest patches always have relatively weaker resilience under the same climatic conditions. Our results imply a relatively higher resilience in arid timberline forest patches than in continuous forests; however, further climate warming and increased drought could possibly cause the disappearance of small forest patches around the arid tree line. This study sheds light on climate change adaptation and provides insight into managing vulnerable semiarid forests. © 2016 John Wiley & Sons Ltd.

Distribution of biomass in an Indiana old-growth forest from 1926 to 1992

Treesearch

Martin A. Spetich; George R. Parker

1998-01-01

We examined the structural and spatial distribution of woody biomass in relationship to disturbance in an Indiana old-growth deciduous forest over a 66-year period. Analysis was done on the core 7.92 ha of a 20.6 ha forest in which every tree 10 cm dbh and over has been tagged and mapped since 1926. Five years are compared - 1926, 1976, 1981, 1986 and 1992....

Ground Layer Plant Species Turnover and Beta Diversity in Southern-European Old-Growth Forests

PubMed Central

Sabatini, Francesco Maria; Burrascano, Sabina; Tuomisto, Hanna; Blasi, Carlo

2014-01-01

Different assembly processes may simultaneously affect local-scale variation of species composition in temperate old-growth forests. Ground layer species diversity reflects chance colonization and persistence of low-dispersal species, as well as fine-scale environmental heterogeneity. The latter depends on both purely abiotic factors, such as soil properties and topography, and factors primarily determined by overstorey structure, such as light availability. Understanding the degree to which plant diversity in old-growth forests is associated with structural heterogeneity and/or to dispersal limitation will help assessing the effectiveness of silvicultural practices that recreate old-growth patterns and structures for the conservation or restoration of plant diversity. We used a nested sampling design to assess fine-scale species turnover, i.e. the proportion of species composition that changes among sampling units, across 11 beech-dominated old-growth forests in Southern Europe. For each stand, we also measured a wide range of environmental and structural variables that might explain ground layer species turnover. Our aim was to quantify the relative importance of dispersal limitation in comparison to that of stand structural heterogeneity while controlling for other sources of environmental heterogeneity. For this purpose, we used multiple regression on distance matrices at the within-stand extent, and mixed effect models at the extent of the whole dataset. Species turnover was best predicted by structural and environmental heterogeneity, especially by differences in light availability and in topsoil nutrient concentration and texture. Spatial distances were significant only in four out of eleven stands with a relatively low explanatory power. This suggests that structural heterogeneity is a more important driver of local-scale ground layer species turnover than dispersal limitation in southern European old-growth beech forests. PMID:24748155

Re-evaluation of forest biomass carbon stocks and lessons from the world's most carbon-dense forests.

PubMed

Keith, Heather; Mackey, Brendan G; Lindenmayer, David B

2009-07-14

From analysis of published global site biomass data (n = 136) from primary forests, we discovered (i) the world's highest known total biomass carbon density (living plus dead) of 1,867 tonnes carbon per ha (average value from 13 sites) occurs in Australian temperate moist Eucalyptus regnans forests, and (ii) average values of the global site biomass data were higher for sampled temperate moist forests (n = 44) than for sampled tropical (n = 36) and boreal (n = 52) forests (n is number of sites per forest biome). Spatially averaged Intergovernmental Panel on Climate Change biome default values are lower than our average site values for temperate moist forests, because the temperate biome contains a diversity of forest ecosystem types that support a range of mature carbon stocks or have a long land-use history with reduced carbon stocks. We describe a framework for identifying forests important for carbon storage based on the factors that account for high biomass carbon densities, including (i) relatively cool temperatures and moderately high precipitation producing rates of fast growth but slow decomposition, and (ii) older forests that are often multiaged and multilayered and have experienced minimal human disturbance. Our results are relevant to negotiations under the United Nations Framework Convention on Climate Change regarding forest conservation, management, and restoration. Conserving forests with large stocks of biomass from deforestation and degradation avoids significant carbon emissions to the atmosphere, irrespective of the source country, and should be among allowable mitigation activities. Similarly, management that allows restoration of a forest's carbon sequestration potential also should be recognized.

Re-evaluation of forest biomass carbon stocks and lessons from the world's most carbon-dense forests

PubMed Central

Keith, Heather; Mackey, Brendan G.; Lindenmayer, David B.

2009-01-01

From analysis of published global site biomass data (n = 136) from primary forests, we discovered (i) the world's highest known total biomass carbon density (living plus dead) of 1,867 tonnes carbon per ha (average value from 13 sites) occurs in Australian temperate moist Eucalyptus regnans forests, and (ii) average values of the global site biomass data were higher for sampled temperate moist forests (n = 44) than for sampled tropical (n = 36) and boreal (n = 52) forests (n is number of sites per forest biome). Spatially averaged Intergovernmental Panel on Climate Change biome default values are lower than our average site values for temperate moist forests, because the temperate biome contains a diversity of forest ecosystem types that support a range of mature carbon stocks or have a long land-use history with reduced carbon stocks. We describe a framework for identifying forests important for carbon storage based on the factors that account for high biomass carbon densities, including (i) relatively cool temperatures and moderately high precipitation producing rates of fast growth but slow decomposition, and (ii) older forests that are often multiaged and multilayered and have experienced minimal human disturbance. Our results are relevant to negotiations under the United Nations Framework Convention on Climate Change regarding forest conservation, management, and restoration. Conserving forests with large stocks of biomass from deforestation and degradation avoids significant carbon emissions to the atmosphere, irrespective of the source country, and should be among allowable mitigation activities. Similarly, management that allows restoration of a forest's carbon sequestration potential also should be recognized. PMID:19553199

Limited Growth Recovery after Drought-Induced Forest Dieback in Very Defoliated Trees of Two Pine Species

PubMed Central

Guada, Guillermo; Camarero, J. Julio; Sánchez-Salguero, Raúl; Cerrillo, Rafael M. Navarro

2016-01-01

Mediterranean pine forests display high resilience after extreme climatic events such as severe droughts. However, recent dry spells causing growth decline and triggering forest dieback challenge the capacity of some forests to recover following major disturbances. To describe how resilient the responses of forests to drought can be, we quantified growth dynamics in plantations of two pine species (Scots pine, black pine) located in south-eastern Spain and showing drought-triggered dieback. Radial growth was characterized at inter- (tree-ring width) and intra-annual (xylogenesis) scales in three defoliation levels. It was assumed that the higher defoliation the more negative the impact of drought on tree growth. Tree-ring width chronologies were built and xylogenesis was characterized 3 years after the last severe drought occurred. Annual growth data and the number of tracheids produced in different stages of xylem formation were related to climate data at several time scales. Drought negatively impacted growth of the most defoliated trees in both pine species. In Scots pine, xylem formation started earlier in the non-defoliated than in the most defoliated trees. Defoliated trees presented the shortest duration of the radial-enlargement phase in both species. On average the most defoliated trees formed 60% of the number of mature tracheids formed by the non-defoliated trees in both species. Since radial enlargement is the xylogenesis phase most tightly related to final growth, this explains why the most defoliated trees grew the least due to their altered xylogenesis phases. Our findings indicate a very limited resilience capacity of drought-defoliated Scots and black pines. Moreover, droughts produce legacy effects on xylogenesis of highly defoliated trees which could not recover previous growth rates and are thus more prone to die. PMID:27066053

Distribution and Characterization of Forested Wetlands in the Carolinas and Virginia

Treesearch

Mark J. Brown

1995-01-01

Recent forest inventories of North Carolina, South Carolina, and Virginia, included sampled for hydric soils, and wetland hydrology. Forest samples that met all 3 of these criteria were classified as forested wetland.This study characterizes wetland forests by extent, owner, age, forest type, physiography, volume, growth, and removals, and evaluates its contribution...

Tree growth and recruitment in a leveed floodplain forest in the Mississippi River Alluvial Valley, USA

USGS Publications Warehouse

Gee, Hugo K.W.; King, Sammy L.; Keim, Richard F.

2014-01-01

Flooding is a defining disturbance in floodplain forests affecting seed germination, seedling establishment, and tree growth. Globally, flood control, including artificial levees, dams, and channelization has altered flood regimes in floodplains. However, a paucity of data are available in regards to the long-term effects of levees on stand establishment and tree growth in floodplain forests. In this study, we used dendrochronological techniques to reconstruct tree recruitment and tree growth over a 90-year period at three stands within a ring levee in the Mississippi River Alluvial Valley (MAV) and to evaluate whether recruitment patterns and tree growth changed following levee construction. We hypothesized that: (1) sugarberry is increasing in dominance and overcup oak (Quercus lyrata) is becoming less dominant since the levee, and that changes in hydrology are playing a greater role than canopy disturbance in these changes in species dominance; and (2) that overcup oak growth has declined following construction of the levee and cessation of overbank flooding whereas that of sugarberry has increased. Recruitment patterns shifted from flood-tolerant overcup oak to flood-intolerant sugarberry (Celtis laevigata) after levee construction. None of the 122 sugarberry trees cored in this study established prior to the levee, but it was the most common species established after the levee. The mechanisms behind the compositional change are unknown, however, the cosmopolitan distribution of overcup oak during the pre-levee period and sugarberry during the post-levee period, the lack of sugarberry establishment in the pre-levee period, and the confinement of overcup oak regeneration to the lowest areas in each stand after harvest in the post-levee period indicate that species-specific responses to flooding and light availability are forcing recruitment patterns. Overcup oak growth was also affected by levee construction, but in contrast to our hypothesis, growth actually

Landslide initiation, runout, and deposition within clearcuts and old-growth forests of Alaska.

Treesearch

A.C. Johnson; D.N. Swanston; K.E. McGee

2000-01-01

More than 300 landslides and debris flows were triggered by an October 1993 storm on Prince of Wales Island, southeast Alaska. Initiation, runout, and deposition patterns of landslides that occurred within clearcuts, second-growth, and old-growth forests were examined. Blowdown and snags, associated with cedar decline and "normal" rates of mortality, were...

Some estimates of growth and mortality from the Malheur National Forest in eastern Oregon.

Treesearch

Donald R. Gedney; Floyd A. Johnson; Vernon E. Hicks

1959-01-01

During 1955-56 an inventory was made of forested land in the Middle Fork Working Circle of the Malheur National Forest to provide information necessary for calculation of the allowable cut and for other management purposes. The growth and mortality estimates in the following report were obtained from this inventory. Although the estimates apply directly to the Middle...

EFRs in the Rocky Mountain Research Station: Understanding patterns of forest growth, weather and disturbance [Chapter 2.8

Treesearch

G. Sam Foster; Todd Mower; Russell Graham; Theresa B. Jain

2014-01-01

How does forest growth integrate weather, insect and disease attach, management actions, and natural disturbance? Which of these has the most impact on forest growth, composition, structure, and change? These questions have animated the activities of scientists of the Rocky Mountain Research Station (RMRS) since its earliest days, and continue to animate our research...

The limited contribution of large trees to annual biomass production in an old-growth tropical forest.

PubMed

Ligot, Gauthier; Gourlet-Fleury, Sylvie; Ouédraogo, Dakis-Yaoba; Morin, Xavier; Bauwens, Sébastien; Baya, Fidele; Brostaux, Yves; Doucet, Jean-Louis; Fayolle, Adeline

2018-04-16

Although the importance of large trees regarding biodiversity and carbon stock in old-growth forests is undeniable, their annual contribution to biomass production and carbon uptake remains poorly studied at the stand level. To clarify the role of large trees in biomass production, we used data of tree growth, mortality, and recruitment monitored during 20 yr in 10 4-ha plots in a species-rich tropical forest (Central African Republic). Using a random block design, three different silvicultural treatments, control, logged, and logged + thinned, were applied in the 10 plots. Annual biomass gains and losses were analyzed in relation to the relative biomass abundance of large trees and by tree size classes using a spatial bootstrap procedure. Although large trees had high individual growth rates and constituted a substantial amount of biomass, stand-level biomass production decreased with the abundance of large trees in all treatments and plots. The contribution of large trees to annual stand-level biomass production appeared limited in comparison to that of small trees. This pattern did not only originate from differences in abundance of small vs. large trees or differences in initial biomass stocks among tree size classes, but also from a reduced relative growth rate of large trees and a relatively constant mortality rate among tree size classes. In a context in which large trees are increasingly gaining attention as being a valuable and a key structural characteristic of natural forests, the present study brought key insights to better gauge the relatively limited role of large trees in annual stand-level biomass production. In terms of carbon uptake, these results suggest, as already demonstrated, a low net carbon uptake of old-growth forests in comparison to that of logged forests. Tropical forests that reach a successional stage with relatively high density of large trees progressively cease to be carbon sinks as large trees contribute sparsely or even

Changes in plant species composition along an elevation gradient in an old-growth bottomland hardwood-Pinus taeda forest in southern Arkansas

Treesearch

Adrian G. Grell; Michael G. Shelton; Eric Heitzman

2005-01-01

Old-growth bottomland hardwood-Pinus taeda L. forests are rare in Arkansas, and the complex relationships between plant communities and environmental conditions have not been well described in these forests. To investigate these relationships, a digital elevation model was developed for a 16.2 ha old-growth bottomland hardwood-Pinus taeda forest in...

The synergistic effect in the Fe-Co bimetallic catalyst system for the growth of carbon nanotube forests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hardeman, D.; Esconjauregui, S., E-mail: cse28@cam.ac.uk; Cartwright, R.

2015-01-28

We report the growth of multi-walled carbon nanotube forests employing an active-active bimetallic Fe-Co catalyst. Using this catalyst system, we observe a synergistic effect by which—in comparison to pure Fe or Co—the height of the forests increases significantly. The homogeneity in the as-grown nanotubes is also improved. By both energy dispersive spectroscopy and in-situ x-ray photoelectron spectroscopy, we show that the catalyst particles consist of Fe and Co, and this dramatically increases the growth rate of the tubes. Bimetallic catalysts are thus potentially useful for synthesising nanotube forests more efficiently.

Germination and initial growth of tree seedlings on deforested and natural forest soil at Dulhazara, Bangladesh.

PubMed

Hossain, M Mohitul

2012-12-01

The destruction of natural forest is increasing due to urbanization, industrialization, settlement and for the agricultural expansion over last few decades, and studies for their recovery need to be undertaken. With this aim, this comparative study was designed to see the effects of deforested soil on germination and growth performance of five different tree species. In the experiment, five species namely Gmelina arborea, Swietenia mahagoni, Dipterocarpus turbinatus, Acacia auriculiformis and Syzygium grande were germinated for six weeks on seedbeds and raised in pots (25cm diameter, 30cm height), that were filled with two soil and type of land use: deforested and adjacent natural forest of Dulhazara Safari Park. Growth performance of seedling was observed up to 15 months based on height, collar diameter and biomass production at the end. Our results showed that the germination rate was almost similar in both type of land uses. Height growth of D. turbinatus, G. arborea and S. mahagoni seedlings was almost similar and A. auriculi formis and S. grande lower in deforested soil compared to natural forest soil, while collar diameter ofA. auriculi formis, G. arborea, S. grande and S. mahagoni lower and D. turbinatus similar in deforested soil compared to natural forest soil. After uprooting at 19 months, S. mahagoni seedlings were showed significantly (p< or =0.05) higher oven dry biomass, D. turbinatus and A. auriculiformis higher, while G. arborea showed significantly (p< or =0.05) lower and S. grande almost similar oven dry biomass in deforested soil compared to natural forest soil. Oven dry biomass of D. turbinatus seedlings at 19 month age in deforested soil was 21.96g (n=5) and in natural forest soil 18.86g (n=5). However, differences in germination rate and growth performance for different tree species indicated that soil are not too much deteriorated through deforestation at Dulhazara and without any failure such deforested lands would be possible to bring under

Temperature and rainfall strongly drive temporal growth variation in Asian tropical forest trees.

PubMed

Vlam, Mart; Baker, Patrick J; Bunyavejchewin, Sarayudh; Zuidema, Pieter A

2014-04-01

Climate change effects on growth rates of tropical trees may lead to alterations in carbon cycling of carbon-rich tropical forests. However, climate sensitivity of broad-leaved lowland tropical trees is poorly understood. Dendrochronology (tree-ring analysis) provides a powerful tool to study the relationship between tropical tree growth and annual climate variability. We aimed to establish climate-growth relationships for five annual-ring forming tree species, using ring-width data from 459 canopy and understory trees from a seasonal tropical forest in western Thailand. Based on 183/459 trees, chronologies with total lengths between 29 and 62 years were produced for four out of five species. Bootstrapped correlation analysis revealed that climate-growth responses were similar among these four species. Growth was significantly negatively correlated with current-year maximum and minimum temperatures, and positively correlated with dry-season precipitation levels. Negative correlations between growth and temperature may be attributed to a positive relationship between temperature and autotrophic respiration rates. The positive relationship between growth and dry-season precipitation levels likely reflects the strong water demand during leaf flush. Mixed-effect models yielded results that were consistent across species: a negative effect of current wet-season maximum temperatures on growth, but also additive positive effects of, for example, prior dry-season maximum temperatures. Our analyses showed that annual growth variability in tropical trees is determined by a combination of both temperature and precipitation variability. With rising temperature, the predominantly negative relationship between temperature and growth may imply decreasing growth rates of tropical trees as a result of global warming.

Crown dynamics and wood production of Douglas-fir trees in an old-growth forest

Treesearch

H. Roaki Ishii; Stephen C. Sillett; Allyson L. Carroll

2017-01-01

Large trees are the most prominent structural features of old-growth forests, which are considered to be globally important carbon sinks. Because of their large size, estimates of biomass and growth of large trees are often based on ground-level measurements (e.g., diameter at breast height, DBH) and little is known about growth dynamics within the crown. As trees...

Seasonal carbon fluxes for an old-growth temperate forest inferred from carbonyl sulphide

NASA Astrophysics Data System (ADS)

Rastogi, Bharat; Jiang, Yueyang; Berkelhammer, Maxwell; Wharton, Sonia; Noone, David; Still, Christopher

2017-04-01

Characterizing and quantifying the processes that control terrestrial ecosystem exchanges of carbon and water are critical for understanding how forested ecosystems respond to a changing climate. A small but increasing number of studies has identified carbonyl sulfide (OCS) as a potential tracer of canopy photosynthesis and stomatal function. Here we present seasonal fluxes of OCS from a 60m tall old-growth temperate forest. An off-axis integrated cavity output spectroscopy analyzer (Los Gatos Research Inc.) was deployed at the Wind River Experimental Forest in Washington (45.8205°N, 121.9519°W) in 2014 and 2015. GPP (Gross Primary Production) is inferred from OCS fluxes and compared with estimates derived from measurements of NEE (Net Ecosystem Exchange) from eddy flux data as well as GPP predictions using a process based model. Our findings seek to resolve scientific questions regarding ecosystem carbon exchange from tall old growth forests, which have a complicated vertical leaf area structure, high above ground biomass and amount and aerial cover of epiphytic vegetation. Estimates of canopy conductance calculated using tower flux data are also combined with measurements of stable isotopologues of CO2 to infer emergent ecosystem properties such as canopy ci/ca and water use efficiency.

Managing burned landscapes: Evaluating future management strategies for resilient forests under a warming climate

Treesearch

K. L. Shive; P. Z. Fule; C. H. Sieg; B. A. Strom; M. E. Hunter

2014-01-01

Climate change effects on forested ecosystems worldwide include increases in drought-related mortality, changes to disturbance regimes and shifts in species distributions. Such climate-induced changes will alter the outcomes of current management strategies, complicating the selection of appropriate strategies to promote forest resilience. We modelled forest growth in...

An Individual-Tree Growth and Yield Prediction System for Even-Aged Natural Shortleaf Pine Forests

Treesearch

Thomas B. Lynch; Kenneth L. Hitch; Michael M. Huebschmann; Paul A. Murphy

1999-01-01

The development of a system of equations that model the growth and development of even-aged natural shortleaf (Pinus echinata Mill.) pine forests is described. The growth prediction system is a distance-independent individual-tree simulator containing equations that predict basal-area growth, survival, total and merchantable heights, and total and...

Thinning, tree-growth, and resistance to multi-year drought in a mixed-conifer forest of northern California

USGS Publications Warehouse

Vernon, Michael J.; Sherriff, Rosemary L.; van Mantgem, Phillip; Kane, Jeffrey M.

2018-01-01

Drought is an important stressor in forest ecosystems that can influence tree vigor and survival. In the U.S., forest managers use two primary management techniques to promote resistance and resilience to drought: prescribed fire and mechanical thinning. Generally applied to reduce fuels and fire hazard, treatments may also reduce competition for resources that may improve tree-growth and reduce mortality during drought. A recent severe and prolonged drought in California provided a natural experiment to investigate tree-growth responses to fuel treatments and climatic stress. We assessed tree-growth from 299 ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii) in treated and untreated stands during severe drought from 2012 to 2015 in the mixed-conifer forests of Whiskeytown National Recreation Area (WNRA) in northern California. The treatment implemented at WNRA removed 34% of live basal area through mechanical thinning with a subsequent pile burning of residual fuels. Tree-growth was positively associated with crown ratio and negatively associated with competition and a 1-year lag of climate water deficit, an index of drought. Douglas-fir generally had higher annual growth than ponderosa pine, although factors affecting growth were the same for both species. Drought resistance, expressed as the ratio between mean growth during drought and mean growth pre-drought, was higher in treated stands compared to untreated stands during both years of severe drought (2014 and 2015) for ponderosa pine but only one year (2014) for Douglas-fir. Thinning improved drought resistance, but tree size, competition and species influenced this response. On-going thinning treatments focused on fuels and fire hazard reduction are likely to be effective at promoting growth and greater drought resistance in dry mixed-conifer forests. Given the likelihood of future droughts, land managers may choose to implement similar treatments to reduce potential impacts.

Functional strategies of tropical dry forest plants in relation to growth form and isotopic composition

NASA Astrophysics Data System (ADS)

Santiago, L. S.; Silvera, K.; Andrade, J. L.; Dawson, T. E.

2017-11-01

Tropical dry forests (TDFs) undergo a substantial dry season in which plant species must endure several months of drought. Although TDFs support a diverse array of plant growth forms, it is not clear how they vary in mechanisms for coping with seasonal drought. We measured organic tissue stable isotopic composition of carbon (δ13C) and nitrogen (δ15N) across six plant growth forms including epiphytes, terrestrial succulents, trees, shrubs, herbs, and vines, and oxygen (δ18O) of four growth forms, to distinguish among patterns of resource acquisition and evaluate mechanisms for surviving annual drought in a lowland tropical dry forest in Yucatan, Mexico. Terrestrial succulent and epiphyte δ13C was around -14‰, indicating photosynthesis through the Crassulacean acid metabolism pathway, and along with one C4 herb were distinct from mean values of all other growth forms, which were between -26 and -29‰ indicating C3 photosynthesis. Mean tissue δ15N across epiphytes was -4.95‰ and was significantly lower than all other growth forms, which had values around +3‰. Tissue N concentration varied significantly among growth forms with epiphytes and terrestrial succulents having significantly lower values of about 1% compared to trees, shrubs, herbs and vines, which were around 3%. Tissue C concentration was highest in trees, shrubs and vines, intermediate in herbs and epiphytes and lowest in terrestrial succulents. δ18O did not vary among growth forms. Overall, our results suggest several water-saving aspects of resource acquisition, including the absolute occurrence of CAM photosynthesis in terrestrial succulents and epiphytes, high concentrations of leaf N in some species, which may facilitate CO2 drawdown by photosynthetic enzymes for a given stomatal conductance, and potentially diverse N sources ranging from atmospheric N in epiphytes with extremely depleted δ15N values, and a large range of δ15N values among trees, many of which are legumes and dry season

Simulating stand climate, phenology, and photosynthesis of a forest stand with a process-based growth model.

PubMed

Rötzer, Thomas; Leuchner, Michael; Nunn, Angela J

2010-07-01

In the face of climate change and accompanying risks, forest management in Europe is becoming increasingly important. Model simulations can help to understand the reactions and feedbacks of a changing environment on tree growth. In order to simulate forest growth based on future climate change scenarios, we tested the basic processes underlying the growth model BALANCE, simulating stand climate (air temperature, photosynthetically active radiation (PAR) and precipitation), tree phenology, and photosynthesis. A mixed stand of 53- to 60-year-old Norway spruce (Picea abies) and European beech (Fagus sylvatica) in Southern Germany was used as a reference. The results show that BALANCE is able to realistically simulate air temperature gradients in a forest stand using air temperature measurements above the canopy and PAR regimes at different heights for single trees inside the canopy. Interception as a central variable for water balance of a forest stand was also estimated. Tree phenology, i.e. bud burst and leaf coloring, could be reproduced convincingly. Simulated photosynthesis rates were in accordance with measured values for beech both in the sun and the shade crown. For spruce, however, some discrepancies in the rates were obvious, probably due to changed environmental conditions after bud break. Overall, BALANCE has shown to respond to scenario simulations of a changing environment (e.g., climate change, change of forest stand structure).

The components of change for an annual forest inventory design

Treesearch

Francis A. Roesch

2007-01-01

The sample design of the USDA Forest Service's Forest Inventory and Analysis Program (FIA) with respect to a three-dimensional population (forest area X time) of tree attributes is formally defined and evaluated. The definitions for both the traditional components of growth, as presented by Meyer (1953, Forest Mensuration), and a discrete analog to the time...

Soil moisture and its role in growth-climate relationships across an aridity gradient in semiarid Pinus halepensis forests.

PubMed

Manrique-Alba, Àngela; Ruiz-Yanetti, Samantha; Moutahir, Hassane; Novak, Klemen; De Luis, Martin; Bellot, Juan

2017-01-01

In Mediterranean areas with limited availability of water, an accurate knowledge of growth response to hydrological variables could contribute to improving management and stability of forest resources. The main goal of this study is to assess the temporal dynamic of soil moisture to better understand the water-growth relationship of Pinus halepensis forests in semiarid areas. The estimates of modelled soil moisture and measured tree growth were used at four sites dominated by afforested Pinus halepensis Mill. in south-eastern Spain with 300 to 609mm mean annual precipitation. Firstly, dendrochronological samples were extracted and the widths of annual tree rings were measured to compute basal area increments (BAI). Secondly, soil moisture was estimated over 20 hydrological years (1992-2012) by means of the HYDROBAL ecohydrological model. Finally, the tree growth was linked, to mean monthly and seasonal temperature, precipitation and soil moisture. Results depict the effect of soil moisture on growth (BAI) and explain 69-73% of the variance in semiarid forests, but only 51% in the subhumid forests. This highlights the fact that that soil moisture is a suitable and promising variable to explain growth variations of afforested Pinus halepensis in semiarid conditions and useful for guiding adaptation plans to respond pro-actively to water-related global challenges. Copyright © 2016 Elsevier B.V. All rights reserved.

Persistence of Native Trees in an Invaded Hawaiian Lowland Wet Forest: Experimental Evaluation of Light and Water Constraints

Treesearch

Jodie R. Schulten; T. Colleen Cole; Susan Cordell; Keiko M. Publico; Rebecca Ostertag; Jaime E. Enoka; Jené D. Michaud

2014-01-01

Hawaiian lowland wet forests are heavily invaded and their restoration is most likely to be successful if native species selected for restoration have efficient resource-use traits. We evaluated growth, survival, and ecophysiological responses of four native and four invasive species in a greenhouse experiment that simulated reduced light and water conditions commonly...

Stand and cohort structures of old-growth Pinus resinosa-dominated forests of northern Minnesota, USA

Treesearch

Shawn Fraver; Brian J. Palik

2012-01-01

The wide range of stand and age-cohort structures in these old-growth P. resinosa stands depicts pre-settlement forests more complex than those of the single-cohort, post-stand-replacing-fire model that has guided regional forest management. Within-stand patchiness of cohort age structures implies disturbances operating at scales smaller than...

Evaluating the impacts of slope aspect on forest dynamic succession in Northwest China based on FAREAST model

NASA Astrophysics Data System (ADS)

Hu, Shanshan; Ma, Jianyong; Shugart, Herman H.; Yan, Xiaodong

2018-03-01

Mountain forests provide the main water resources and lumber for Northwest China. The understanding of the differences in forests growing among individual slope aspects in mountainous regions is of great significance to the wise management and planning of these natural systems. The aim of this study was to investigate the impacts of slope aspect on forest dynamic succession in Northwest China by using the dynamic forest succession model (FAREAST). First, the simulated forest composition and vertical forest zonation produced by the model were compared against recorded data in three sub-regions of the Altai Mountains. The FAREAST model accurately reproduced the vertical zonation, forest composition, growth curves of the dominant species (Larix sibirica), and forest biomass in the Altai Mountains. Transitions along the forest zones of the Altai Mountains averaged about a 400 m difference between the northern and southern sites. Biomass for forests on north-facing slopes were 11.0, 15.3 and 55.9 t C ha-1 higher than for south-facing slopes in the Northeast, Central and Southeast sub-regions, respectively. Second, our analyses showed that the FAREAST model can be used to predict dynamic forest succession in Northwest China under the influence of slope and aspect. In the Altai Mountains, the north-facing slopes supported the best forest growth, followed by the west- and east-facing slopes. South-facing slopes consistently exhibited the lowest growth, biomass storage and forest diversity.

Evaluation of forest structure, biomass and carbon sequestration in subtropical pristine forests of SW China.

PubMed

Nizami, Syed Moazzam; Yiping, Zhang; Zheng, Zheng; Zhiyun, Lu; Guoping, Yang; Liqing, Sha

2017-03-01

Very old natural forests comprising the species of Fagaceae (Lithocarpus xylocarpus, Castanopsis wattii, Lithocarpus hancei) have been prevailing since years in the Ailaoshan Mountain Nature Reserve (AMNR) SW China. Within these forest trees, density is quite variable. We studied the forest structure, stand dynamics and carbon density at two different sites to know the main factors which drives carbon sequestration process in old forests by considering the following questions: How much is the carbon density in these forest trees of different DBH (diameter at breast height)? How much carbon potential possessed by dominant species of these forests? How vegetation carbon is distributed in these forests? Which species shows high carbon sequestration? What are the physiochemical properties of soil in these forests? Five-year (2005-2010) tree growth data from permanently established plots in the AMNR was analysed for species composition, density, stem diameter (DBH), height and carbon (C) density both in aboveground and belowground vegetation biomass. Our study indicated that among two comparative sites, overall 54 species of 16 different families were present. The stem density, height, C density and soil properties varied significantly with time among the sites showing uneven distribution across the forests. Among the dominant species, L. xylocarpus represents 30% of the total carbon on site 1 while C. wattii represents 50% of the total carbon on site 2. The average C density ranged from 176.35 to 243.97 t C ha -1 . The study emphasized that there is generous degree to expand the carbon stocking in this AMNR through scientific management gearing towards conservation of old trees and planting of potentially high carbon sequestering species on good site quality areas.

Nutrient foraging strategies are associated with productivity and population growth in forest shrubs.

PubMed

Caplan, Joshua S; Stone, Bram W G; Faillace, Cara A; Lafond, Jonathan J; Baumgarten, Joni M; Mozdzer, Thomas J; Dighton, John; Meiners, Scott J; Grabosky, Jason C; Ehrenfeld, Joan G

2017-04-01

Temperate deciduous forest understoreys are experiencing widespread changes in community composition, concurrent with increases in rates of nitrogen supply. These shifts in plant abundance may be driven by interspecific differences in nutrient foraging (i.e. conservative vs. acquisitive strategies) and, thus, adaptation to contemporary nutrient loading conditions. This study sought to determine if interspecific differences in nutrient foraging could help explain patterns of shrub success and decline in eastern North American forests. Using plants grown in a common garden, fine root traits associated with nutrient foraging were measured for six shrub species. Traits included the mean and skewness of the root diameter distribution, specific root length (SRL), C:N ratio, root tissue density, arbuscular mycorrhizal colonization and foraging precision. Above- and below-ground productivity were also determined for the same plants, and population growth rates were estimated using data from a long-term study of community dynamics. Root traits were compared among species and associations among root traits, measures of productivity and rates of population growth were evaluated. Species fell into groups having thick or thin root forms, which correspond to conservative vs. acquisitive nutrient foraging strategies. Interspecific variation in root morphology and tissue construction correlated with measures of productivity and rates of cover expansion. Of the four species with acquisitive traits, three were introduced species that have become invasive in recent decades, and the fourth was a weedy native. In contrast, the two species with conservative traits were historically dominant shrubs that have declined in abundance in eastern North American forests. In forest understoreys of eastern North America, elevated nutrient availability may impose a filter on species success in addition to above-ground processes such as herbivory and overstorey canopy conditions. Shrubs that have

Forest health monitoring indicators and their interpretability: a Lithuanian case study

Treesearch

Romualdas Kuknys; Algirdas Augustaitis

1998-01-01

Growth and productivity of forests are important indicators for understanding the general condition and health of forests. It is very important that indicators detected during monitoring procedures afford an opportunity for direct or indirect evaluation of forest productivity and its natural and anthropogenic changes. Analysis of the U.S. Forest Health Monitoring (FHM...

Contributions of insects and droughts to growth decline of trembling aspen mixed boreal forest of western Canada.

PubMed

Chen, Lei; Huang, Jian-Guo; Dawson, Andria; Zhai, Lihong; Stadt, Kenneth J; Comeau, Philip G; Whitehouse, Caroline

2018-02-01

Insects, diseases, fire and drought and other disturbances associated with global climate change contribute to forest decline and mortality in many parts of the world. Forest decline and mortality related to drought or insect outbreaks have been observed in North American aspen forests. However, little research has been done to partition and estimate their relative contributions to growth declines. In this study, we combined tree-ring width and basal area increment series from 40 trembling aspen (Populus tremuloides Michx.) sites along a latitudinal gradient (from 52° to 58°N) in western Canada and attempted to investigate the effect of drought and insect outbreaks on growth decline, and simultaneously partition and quantify their relative contributions. Results indicated that the influence of drought on forest decline was stronger than insect outbreaks, although both had significant effects. Furthermore, the influence of drought and insect outbreaks showed spatiotemporal variability. In addition, our data suggest that insect outbreaks could be triggered by warmer early spring temperature instead of drought, implicating that potentially increased insect outbreaks are expected with continued warming springs, which may further exacerbate growth decline and death in North America aspen mixed forests. © 2017 John Wiley & Sons Ltd.

Variability in solar radiation and temperature explains observed patterns and trends in tree growth rates across four tropical forests.

PubMed

Dong, Shirley Xiaobi; Davies, Stuart J; Ashton, Peter S; Bunyavejchewin, Sarayudh; Supardi, M N Nur; Kassim, Abd Rahman; Tan, Sylvester; Moorcroft, Paul R

2012-10-07

The response of tropical forests to global climate variability and change remains poorly understood. Results from long-term studies of permanent forest plots have reported different, and in some cases opposing trends in tropical forest dynamics. In this study, we examined changes in tree growth rates at four long-term permanent tropical forest research plots in relation to variation in solar radiation, temperature and precipitation. Temporal variation in the stand-level growth rates measured at five-year intervals was found to be positively correlated with variation in incoming solar radiation and negatively related to temporal variation in night-time temperatures. Taken alone, neither solar radiation variability nor the effects of night-time temperatures can account for the observed temporal variation in tree growth rates across sites, but when considered together, these two climate variables account for most of the observed temporal variability in tree growth rates. Further analysis indicates that the stand-level response is primarily driven by the responses of smaller-sized trees (less than 20 cm in diameter). The combined temperature and radiation responses identified in this study provide a potential explanation for the conflicting patterns in tree growth rates found in previous studies.

Soil biota effects on clonal growth and flowering in the forest herb Stachys sylvatica

NASA Astrophysics Data System (ADS)

de la Peña, Eduardo; Bonte, Dries

2011-03-01

The composition of a soil community can vary drastically at extremely short distances. Therefore, plants from any given population can be expected to experience strong differences in belowground biotic interactions. Although it is well recognized that the soil biota plays a significant role in the structure and dynamics of plant communities, plastic responses in growth strategies as a function of soil biotic interactions have received little attention. In this study, we question whether the biotic soil context from two forest associated contrasting environments (the forest understory and the hedgerows) determines the balance between clonal growth and flowering of the perennial Stachys sylvatica. Using artificial soils, we compared the growth responses of this species following inoculation with the mycorrhizal and microbial community extracted either from rhizospheric soil of the forest understory or from the hedgerows. The microbial context had a strong effect on plant functional traits, determining the production of runners and inflorescences. Plants inoculated with the hedgerow community had a greater biomass, larger number of runners, and lower resource investment in flower production than was seen in plants inoculated with the understory microbial community. The obtained results illustrate that belowground biotic interactions are essential to understand basic plastic growth responses determinant for plant establishment and survival. The interactions with microbial communities from two contrasting habitats resulted in two different, and presumably adaptive, growth strategies that were optimal for the conditions prevalent in the environments compared; and they are as such an essential factor to understand plant-plant, plant-animal interactions and the dispersal capacities of clonal plants.

Effects of intensive forest management practices on insect infestation levels and loblolly pine growth

Treesearch

John T. Nowak; C. Wayne Berisford

2000-01-01

Intensive forest management practices have been shown to increase tree growth and shorten rotation time. However, they may also lead to an increased need for insect pest management because of higher infestation levels and lower action thresholds. To investigate the relationship between intensive management practices arid insect infestation, maximum growth potential...

Downstream impacts of a Central Amazonian hydroelectric dam on tree growth and mortality in floodplain forests

NASA Astrophysics Data System (ADS)

Resende, A. F. D.; Silva, T. S. F.; Silva, J. D. S.; Piedade, M. T. F.; Streher, A. S.; Ferreira-Ferreira, J.; Schongart, J.

2017-12-01

The flood pulse of large Amazonian Rivers is characterized by predictable high- and low-water periods during the annual cycle, and is the main driving force in the floodplains regulating decomposition, nutrient cycles, productivity, life cycles and growth rhythms of floodplains' biota. Over at least 20 millions of years, tree species in these ecosystems developed complex adaptative mechanisms to tolerate flooding, such as the tree species Macrolobium acaciifolium (Fabaceae) and Eschweilera tenuifolia (Lecythidaceae) occupying the lower topographic positions in the floodplain forests along the oligothrophic black-water rivers. Tree growth occurs mainly during terrestrial phase, while during the aquatic phase the anoxic conditions result into a cambial dormancy and formation of annual tree rings. The hydroelectric dam Balbina which was installed in the Uatumã River (central Amazonia) during the 1980s altered significantly the flood pulse regime resulting into higher minimum and lower maximum annual water levels. The suppression of the terrestrial phase caused large-scale mortality of flood-adapted trees growing on the lower topographic positions, as evidenced by radiocarbon dating and cross-dating techniques (dendrochronology). In this study we estimated the extension of dead forests using high resolution ALOS/PALSAR radar images, for their detection along a fluvial distance of more than 280 km downstream of the power plant. Further we analyzed tree growth of 60 living individuals of E. tenuifolia by tree-ring analyses comparing the post- and pre-dam periods. We evaluated the impacts of the altered hydrological regime on tree growth considering ontogenetic effects and the fluvial distance of the trees to the dam. Since the Balbina power plant started operating the associated igapó forests lost about 11% of its cover. We found a significant reduction of tree growth of E. tenuifolia during the post-dam period as a consequence of the increasing aquatic phase duration

Determining successional stage of temperate coniferous forests with Landsat satellite data

NASA Technical Reports Server (NTRS)

Fiorella, Maria; Ripple, William J.

1993-01-01

Thematic Mapper (TM) digital imagery was used to map forest successional stages and to evaluate spectral differences between old-growth and mature forests in the central Cascade Range of Oregon. Relative sun incidence values were incorporated into the successional stage classification to compensate for topographic induced variation. Relative sun incidence improved the classification accuracy of young successional stages, but did not improve the classification accuracy of older, closed canopy forest classes or overall accuracy. TM bands 1, 2, and 4; the normalized difference vegetation index; and TM 4/3, 4/5, and 4/7 band ratio values for o|d-growth forests were found to be significantly lower than the values of mature forests. The Tasseled Cap features of brightness, greenness, and wetness also had significantly lower old-growth values as compared to mature forest values .

Response of a boreal forest to canopy opening: assessing vertical and lateral tree growth with multi-temporal lidar data.

PubMed

Vepakomma, Udayalakshmi; St-Onge, Benoit; Kneeshaw, Daniel

2011-01-01

Fine-scale height-growth response of boreal trees to canopy openings is difficult to measure from the ground, and there are important limitations in using stereophotogrammetry in defining gaps and determining individual crowns and height. However, precise knowledge on height growth response to different openings is critical for refining partial harvesting techniques. In this study, we question whether conifers and hardwoods respond equally in terms of sapling growth or lateral growth to openings. We also ask to what distance gaps affect tree growth into the forest. We use multi-temporal lidar to characterize tree/sapling height and lateral growth responses over five years to canopy openings and high resolution images to identify conifers and hardwoods. Species-class-wise height-growth patterns of trees/saplings in various neighborhood contexts were determined across a 6-km matrix of Canadian boreal mixed deciduous coniferous forests. We then use statistical techniques to probe how these growth responses vary by spatial location with respect to the gap edge. Results confirm that both mechanisms of gap closure contribute to the closing of canopies at a rate of 1.2% per annum. Evidence also shows that both hardwood and conifer gap edge trees have a similar lateral growth (average of 22 cm/yr) and similar rates of height growth irrespective of their location and initial height. Height growth of all saplings, however, was strongly dependent on their position within the gap and the size of the gap. Results suggest that hardwood and softwood saplings in gaps have greatest growth rates at distances of 0.5-2 m and 1.5-4 m from the gap edge and in openings smaller than 800 m2 and 250 m2, respectively. Gap effects on the height growth of trees in the intact forest were evident up to 30 m and 20 m from gap edges for hardwood and softwood overstory trees, respectively. Our results thus suggest that foresters should consider silvicultural techniques that create many small

Historical growth plots in the Pacific Southwest

Treesearch

Lawrence A. Rabin; William W. Oliver; Robert F. Powers; Martin W. Ritchie; Matt D. Busse; Eric E. Knapp

2009-01-01

In the past, researchers from the Pacific Southwest Research Station (PSW) undertook forest growth studies to evaluate how best to manage timber resources. However, historical and future data collected at PSW growth plots also have the potential to increase our understanding of the ecological processes occurring in our forests and shed light on national issues of...

Growth responses of trees and understory plants to nitrogen fertilization in a subtropical forest in China

NASA Astrophysics Data System (ADS)

Tian, Di; Li, Peng; Fang, Wenjing; Xu, Jun; Luo, Yongkai; Yan, Zhengbing; Zhu, Biao; Wang, Jingjing; Xu, Xiaoniu; Fang, Jingyun

2017-07-01

Reactive nitrogen (N) increase in the biosphere has been a noteworthy aspect of global change, producing considerable ecological effects on the functioning and dynamics of the terrestrial ecosystems. A number of observational studies have explored responses of plants to experimentally simulated N enrichment in boreal and temperate forests. Here we investigate how the dominant trees and different understory plants respond to experimental N enrichment in a subtropical forest in China. We conducted a 3.4-year N fertilization experiment in an old-aged subtropical evergreen broad-leaved forest in eastern China with three treatment levels applied to nine 20 m × 20 m plots and replicated in three blocks. We divided the plants into trees, saplings, shrubs (including tree seedlings), and ground-cover plants (ferns) according to the growth forms, and then measured the absolute and relative basal area increments of trees and saplings and the aboveground biomass of understory shrubs and ferns. We further grouped individuals of the dominant tree species, Castanopsis eyrei, into three size classes to investigate their respective growth responses to the N fertilization. Our results showed that the plot-averaged absolute and relative growth rates of basal area and aboveground biomass of trees were not affected by N fertilization. Across the individuals of C. eyrei, the small trees with a DBH (diameter at breast height) of 5-10 cm declined by 66.4 and 59.5 %, respectively, in N50 (50 kg N ha-1 yr-1) and N100 fertilized plots (100 kg N ha-1 yr-1), while the growth of median and large trees with a DBH of > 10 cm did not significantly change with the N fertilization. The growth rate of small trees, saplings, and the aboveground biomass of understory shrubs and ground-cover ferns decreased significantly in the N-fertilized plots. Our findings suggested that N might not be a limiting nutrient in this mature subtropical forest, and that the limitation of other nutrients in the forest

Abundance and Size Distribution of Cavity Trees in Second-Growth and Old-Growth Central Hardwood Forests

Treesearch

Zhaofei Fan; Stephen R. Shifley; Martin A. Spetich; Frank R. Thompson III; David R. Larsen

2005-01-01

In central hardwood forests, mean cavity-tree abundance increases with increasing standsize class (seedling/sapling, pole, sawtimber, old-growth). However, within a size class, the number of cavity trees is highly variable among 0.1-ha inventory plots. Plots in young stands are most likely to have no cavity trees, but some plots may have more than 50 cavity trees/ha....

Abundance and size distribution of cavity trees in second-growth and old-growth central hardwood forests

Treesearch

Zhaofei Fan; Stephen R. Shifley; Martin A. Spetich; Frank R. Thompson; David R. Larsen

2005-01-01

In central hardwood forests, mean cavity-tree abundance increases with increasing standsize class (seedling/sapling, pole, sawtimber, old-growth). However, within a size class, the number of cavity trees is highly variable among 0.1-ha inventory plots. Plots in young stands are most likely to have no cavity trees, but some plots may have more than 50 cavity trees/ha....

A regional-scale survey and analysis of forest growth and mortality as affected by site and stand factors and acidic deposition

Treesearch

Robert T. Brooks

1994-01-01

Regression analyses were used to identify factors most closely related to species growth and mortality on continuous forest survey plots in Pennsylvania. In 1985, 200 plots with two prior measurements (in the 1960s and 1970s) were selected and measured for a third time to determine periodic forest growth and mortality rates. Growth and mortality were analyzed for...

Implications of mechanistic modeling of drought effects on growth and competition in forest landscape models

Treesearch

Eric J. Gustafson; Arjan M. G. De Bruijn; Brian R. Miranda; Brian R. Sturtevant; J. Thompson

2016-01-01

The incidence of drought is expected to increase worldwide as a factor structuring forested landscapes. Ecophysiological mechanisms are being added to Forest Landscape Models (FLMs) to increase their robustness to the novel environmental conditions of the future (including drought), but their behavior has not been evaluated for mixed temperate forests. We evaluated...

Soil-calcium depletion linked to acid rain and forest growth in the eastern United States

USGS Publications Warehouse

Lawrence, Gregory B.; Huntington, T.G.

1999-01-01

Since the discovery of acid rain in the 1970's, scientists have been concerned that deposition of acids could cause depletion of calcium in forest soils. Research in the 1980's showed that the amount of calcium in forest soils is controlled by several factors that are difficult to measure. Further research in the 1990's, including several studies by the U.S. Geological Survey, has shown that (1) calcium in forest soils has decreased at locations in the northeastern and southeastern U.S., and (2) acid rain and forest growth (uptake of calcium from the soil by roots) are both factors contributing to calcium depletion.

Tropical rain forest tree growth and atmospheric carbon dynamics linked to interannual temperature variation during 1984–2000

PubMed Central

Clark, D. A.; Piper, S. C.; Keeling, C. D.; Clark, D. B.

2003-01-01

During 1984–2000, canopy tree growth in old-growth tropical rain forest at La Selva, Costa Rica, varied >2-fold among years. The trees' annual diameter increments in this 16-yr period were negatively correlated with annual means of daily minimum temperatures. The tree growth variations also negatively covaried with the net carbon exchange of the terrestrial tropics as a whole, as inferred from nearly pole-to-pole measurements of atmospheric carbon dioxide (CO2) interpreted by an inverse tracer–transport model. Strong reductions in tree growth and large inferred tropical releases of CO2 to the atmosphere occurred during the record-hot 1997–1998 El Niño. These and other recent findings are consistent with decreased net primary production in tropical forests in the warmer years of the last two decades. As has been projected by recent process model studies, such a sensitivity of tropical forest productivity to on-going climate change would accelerate the rate of atmospheric CO2 accumulation. PMID:12719545

Composition, structure, and dendroecology of an old-growth Quercus forest on the tablelands of the Cumberland Plateau, USA.

Treesearch

Justin L. Hart; Stacy L. Clark; Scott J. Torreano; Megan L. Buchanan

2011-01-01

Forest reconstructions provide information on the processes that influence forest development and successional patterns. In this study, we quantified woody species composition, stand structure, and radial growth patterns of individual Quercus trees to document the processes that shaped a forest on the Cumberland Plateau in Tennessee over the past three centuries. The...

Long tree-ring chronologies provide evidence of recent tree growth decrease in a Central African tropical forest.

PubMed

Battipaglia, Giovanna; Zalloni, Enrica; Castaldi, Simona; Marzaioli, Fabio; Cazzolla-Gatti, Roberto; Lasserre, Bruno; Tognetti, Roberto; Marchetti, Marco; Valentini, Riccardo

2015-01-01

It is still unclear whether the exponential rise of atmospheric CO2 concentration has produced a fertilization effect on tropical forests, thus incrementing their growth rate, in the last two centuries. As many factors affect tree growth patterns, short -term studies might be influenced by the confounding effect of several interacting environmental variables on plant growth. Long-term analyses of tree growth can elucidate long-term trends of plant growth response to dominant drivers. The study of annual rings, applied to long tree-ring chronologies in tropical forest trees enables such analysis. Long-term tree-ring chronologies of three widespread African species were measured in Central Africa to analyze the growth of trees over the last two centuries. Growth trends were correlated to changes in global atmospheric CO2 concentration and local variations in the main climatic drivers, temperature and rainfall. Our results provided no evidence for a fertilization effect of CO2 on tree growth. On the contrary, an overall growth decline was observed for all three species in the last century, which appears to be significantly correlated to the increase in local temperature. These findings provide additional support to the global observations of a slowing down of C sequestration in the trunks of forest trees in recent decades. Data indicate that the CO2 increase alone has not been sufficient to obtain a tree growth increase in tropical trees. The effect of other changing environmental factors, like temperature, may have overridden the fertilization effect of CO2.

Long Tree-Ring Chronologies Provide Evidence of Recent Tree Growth Decrease in a Central African Tropical Forest

PubMed Central

Battipaglia, Giovanna; Zalloni, Enrica; Castaldi, Simona; Marzaioli, Fabio; Cazzolla- Gatti, Roberto; Lasserre, Bruno; Tognetti, Roberto; Marchetti, Marco; Valentini, Riccardo

2015-01-01

It is still unclear whether the exponential rise of atmospheric CO2 concentration has produced a fertilization effect on tropical forests, thus incrementing their growth rate, in the last two centuries. As many factors affect tree growth patterns, short -term studies might be influenced by the confounding effect of several interacting environmental variables on plant growth. Long-term analyses of tree growth can elucidate long-term trends of plant growth response to dominant drivers. The study of annual rings, applied to long tree-ring chronologies in tropical forest trees enables such analysis. Long-term tree-ring chronologies of three widespread African species were measured in Central Africa to analyze the growth of trees over the last two centuries. Growth trends were correlated to changes in global atmospheric CO2 concentration and local variations in the main climatic drivers, temperature and rainfall. Our results provided no evidence for a fertilization effect of CO2 on tree growth. On the contrary, an overall growth decline was observed for all three species in the last century, which appears to be significantly correlated to the increase in local temperature. These findings provide additional support to the global observations of a slowing down of C sequestration in the trunks of forest trees in recent decades. Data indicate that the CO2 increase alone has not been sufficient to obtain a tree growth increase in tropical trees. The effect of other changing environmental factors, like temperature, may have overridden the fertilization effect of CO2. PMID:25806946

Disturbance legacies and climate jointly drive tree growth and mortality in an intensively studied boreal forest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bond-Lamberty, Benjamin; Rocha, Adrian; Calvin, Katherine V.

2014-01-01

How will regional growth and mortality change with even relatively small climate shifts, even independent of catastrophic disturbances? This question is particularly acute for the North American boreal forest, which is carbon-dense and subject The goals of this study were to combine dendrochronological sampling, inventory records, and machine-learning algorithms to understand how tree growth and death have changed at one highly studied site (Northern Old Black Spruce, NOBS) in the central Canadian boreal forest. Over the 1999-2012 inventory period, mean DBH increased even as stand density and basal area declined significantly from 41.3 to 37.5 m2 ha-1. Tree mortality averagedmore » 1.4±0.6% yr-1, with most mortality occurring in medium-sized trees. A combined tree ring chronology constructed from 2001, 2004, and 2012 sampling showed several periods of extreme growth depression, with increased mortality lagging depressed growth by ~5 years. Minimum and maximum air temperatures exerted a negative influence on tree growth, while precipitation and climate moisture index had a positive effect; both current- and previous-year data exerted significant effects. Models based on these variables explained 23-44% of the ring-width variability. There have been at least one, and probably two, significant recruitment episodes since stand initiation, and we infer that past climate extremes led to significant NOBS mortality still visible in the current forest structure. These results imply that a combination of successional and demographic processes, along with mortality driven by abiotic factors, continue to affect the stand, with significant implications for our understanding of previous work at NOBS and the sustainable management of regional forests.« less

Revision and application of the LINKAGES model to simulate forest growth in central hardwood landscapes in response to climate change

Treesearch

William D. Dijak; Brice B. Hanberry; Jacob S. Fraser; Hong S. He; Wen J. Wang; Frank R. Thompson

2017-01-01

Context. Global climate change impacts forest growth and methods of modeling those impacts at the landscape scale are needed to forecast future forest species composition change and abundance. Changes in forest landscapes will affect ecosystem processes and services such as succession and disturbance, wildlife habitat, and production of forest...

Canopy gaps affect long-term patterns of tree growth and mortality in mature and old-growth forests in the Pacific Northwest

Treesearch

Andrew N. Gray; Thomas A. Spies; Robert J. Pabst

2012-01-01

Canopy gaps created by tree mortality can affect the speed and trajectory of vegetation growth. Species’ population dynamics, and spatial heterogeneity in mature forests. Most studies focus on plant development within gaps, yet gaps also affect the mortality and growth of surrounding trees, which influence shading and root encroachment into gaps and determine whether,...

[Evaluation of economic forest ecosystem services in China].

PubMed

Wang, Bing; Lu, Shao-Wei

2009-02-01

This paper quantitatively evaluated the economic forest ecosystem services in the provinces of China in 2003, based on the long-term and continuous observations of economic forest ecosystems in this country, the sixth China national forest resources inventory data, and the price parameter data from the authorities in the world, and by applying the law of market value, the method of substitution of the expenses, and the law of the shadow project. The results showed that in 2003, the total value of economic forest ecosystem services in China was 11763.39 x 10(8) yuan, and the total value of the products from economic forests occupied 19.3% of the total ecosystem services value, which indicated that the economic forests not only provided society direct products, but also exhibited enormous eco-economic value. The service value of the functions of economic forests was in the order of water storage > C fixation and O2 release > biodiversity conservation > erosion control > air quality purification > nutrient cycle. The spatial pattern of economic forest ecosystem services in the provinces of China had the same trend with the spatial distribution of water and heat resources and biodiversity. To understand the differences of economic forest ecosystem services in the provinces of China was of significance in alternating the irrational arrangement of our present forestry production, diminishing the abuses of forest management, and establishing high grade, high efficient, and modernized economic forests.

Regeneration patterns of northern white cedar, an old-growth forest dominant

USGS Publications Warehouse

Scott, Michael L.; Murphy, Peter G.

1987-01-01

Regeneration of Thuja occidentalis L. was examined in an old-growth dune forest on South Manitou Island, Michigan. To estimate the current status of cedar regeneration, we determined size structure of seedlings and stems and analyzed present patterns of establishment and persistence relative to substrate type. There has been a shift in the pattern of cedar establishment from soil to log substrates. While 97% of all stems ≥15 cm dbh are associated with a soil substrate, 81% of stems ≥2.5cm-25 cm tall. There was no significant relationship between the state of log decay and the density of seedlings >25 cm in height, indicating that long-term survival is not dependent on the degree of log decomposition. However, survival on logs is associated with canopy openings. Seedlings >25 cm tall were associated with gaps, and 78% of cedar stems (≥2.5 cm dbh) on logs were associated with a single windthrow gap. Thus, current cedar regeneration in this old-growth forest depends on logs and the canopy openings associated with them.

Tree seedling growth and mortality responses to manipulations of calcium and aluminum in a northern hardwood forest

Treesearch

Richard K. Kobe; Gene E. Likens; Christopher Eagar

2002-01-01

To assess potential forest compositional responses to exchangeable soil calcium (Caexch) and aluminum (Alexch), we characterized light-dependent growth and mortality of tree seedlings under amendments of CaCl2 and AlCl3 at Hubbard Brook Experimental Forest (HBEF), New Hampshire...

Two decades of compositional and structural change in deciduous old-growth forests of Indiana, USA

Treesearch

Christy A. Lowney; Bradley D. Graham; Martin A. Spetich; Stephen R. Shifley; Michael R. Saunders; Michael A. Jenkins

2015-01-01

AimsUsing a network of permanent plots, we determined how multiple old-growth forests changed over an 18–19-year period at a statewide scale. This examination of change allowed us to assess how the compositional and structural stability of each forest varied with site characteristics (topography, physiography and productivity)...

Modelling recolonization of second-growth forest stands by the north american red squirrel Tamiasciurus hudsonicus.

PubMed

Nyquist, B; Tyson, R; Larsen, K

2007-05-01

In this paper, we present a model for source-sink population dynamics where the locations of source and sink habitats change over time. We do this in the context of the population dynamics of the North American red squirrel, Tamiasciurus hudsonicus, within a forest environment subject to harvesting and regrowth. Harvested patches of forest are initially sinks, then eventually become source habitat again as the forest regrows. At the same time, each harvested patch is gradually recolonized by squirrels from other forest patches. We are interested in the interaction of forest harvesting dynamics with squirrel population dynamics. This depends on the harvesting schedule, and on the choices squirrels make when deciding whether to settle in a mature forest patch or in a recently harvested patch. We find that the time it takes for a second-growth forest patch to be recolonized at the mature forest level is longer than the time required for the habitat quality to be restored to the mature forest level. We also notice that recolonization pressure decreases squirrel populations in neighbouring patches. The connectivity between forest patches and the cutting schedule used also affect the time course of recolonization and steady-state population levels.

Fragmentation, topography, and forest age modulate impacts of drought on a tropical forested landscape in eastern Puerto Rico

NASA Astrophysics Data System (ADS)

Uriarte, M.; Schwartz, N.; Budsock, A.

2017-12-01

Naturally regenerating second-growth forests account for ca. 50% of tropical forest cover and provide key ecosystem services. Understanding climate impacts on these ecosystems is critical for developing effective mitigation programs. Differences in environmental conditions and landscape context from old-growth forests may exacerbate climate impacts on second-growth stands. Nearly 70% of forest regeneration is occurring in hilly, upland, or mountain regions; a large proportion of second-growth forests are also fragmented. The effects of drought at the landscape scale, however, and the factors that modulate landscape heterogeneity in drought impacts remain understudied. Heterogeneity in soil moisture, light, and temperature in fragmented, topographically complex landscapes is likely to influence climate impacts on these forests. We examine impacts of a severe drought in 2015 on a forested landscape in Puerto Rico using two anomalies in vegetation indices. The study landscape is fragmented and topographically complex and includes old- and second-growth forests. We consider how topography (slope, aspect), fragmentation (distance to forest edge, patch size), and forest age (old- vs second-growth) modulate landscape heterogeneity of drought impacts and recovery from drought. Drought impacts were more severe in second-growth forests than in old-growth stands. Both topography and forest fragmentation influences the magnitude of drought impacts. Forest growing in steep areas, south facing slopes, small patches, and closer to forest edges exhibited more marked responses to drought. Forest recovery from drought was greater in second-growth forests and south facing slopes but slower in small patches and closer to forest edges. These findings are congruent with studies of drought impacts on tree growth in the study region. Together these results demonstrate the need for a multi-scalar approach to the study of drought impacts on tropical forests.

Can a growth model be used to describe forest carbon and water balance after fuel reduction burning in temperate forests?

PubMed

Gharun, Mana; Possell, Malcolm; Vervoort, R Willem; Adams, Mark A; Bell, Tina L

2018-02-15

Empirical evidence from Australia shows that fuel reduction burning significantly reduces the incidence and extent of unplanned fires. However, the integration of environmental values into fire management operations is not yet well-defined and requires further research and development. WAVES, a plant growth model that incorporates Soil-Vegetation-Atmosphere Transfer, was used to simulate the hydrological and ecological effects of three fuel management scenarios on a forest ecosystem. WAVES was applied using inputs from a set of forest plots for one year after three potential scenarios: (1) all litter removed, (2) all litter and 50% of the understorey removed, (3) all litter and understorey removed. Modelled outputs were compared with sites modelled with no-fuel reduction treatment (Unburnt). The key change between unburnt and fuel reduced forests was a significant increase in soil moisture after fire. Predictions of the recovery of aboveground carbon as plant biomass were driven by model structure and thus variability in available light and soil moisture at a local scale. Similarly, effects of fuel reduction burning on water processes were mainly due to changes in vegetation interception capacity (i.e. regrowth) and soil evaporation. Predicted effects of fuel reduction burning on total evapotranspiration (ET) - the major component of water balance - were marginal and not significant, even though a considerable proportion of ET had effectively been transferred from understorey to overstorey. In common with many plant growth models, outputs from WAVES are dictated by the assumption that overstorey trees continue to grow irrespective of their age or stage of maturity. Large areas of eucalypt forests and woodlands in SE Australia are well beyond their aggrading phase and are instead over-mature. The ability of these forests to rapidly respond to greater availability of water remains uncertain. Copyright © 2017 Elsevier B.V. All rights reserved.

Population growth and the decline of natural Southern yellow pine forests

Treesearch

David B. South; Edward R. Buckner

2004-01-01

Population growth has created social and economic pressures that affect the sustainability of naturally regenerated southern yellow pine forests. Major causes of this decline include (1) a shift in public attitudes regarding woods burning (from one favoring it to one that favors fire suppression) and (2) an increase in land values (especially near urban centers). The...

Classification and evaluation for forest sites in the Cumberland Mountains

Treesearch

Glendon W. Smalley

1984-01-01

This report classifies and evaluates forest sites in the Cumberland Mountains (fig. 1) for the management of several commercially valuable tree species. It provides forest managers with a land classification system that will enable them to subdivide forest land into logical segments (landtypes), allow them to rate productivity, and alert them to any limitations and...

Upland log volumes and conifer establishment patterns in two northern, upland old-growth redwood forests, a brief synopsis

Treesearch

Daniel J. Porter; John O. Sawyer

2007-01-01

We characterized the volume, weight and top surface area of naturally fallen logs in an old-growth redwood forest, and quantified conifer recruit densities on these logs and on the surrounding forest floor. We report significantly greater conifer recruit densities on log substrates as compared to the forest floor. Log substrate availability was calculated on a per...

Accelerating forest growth enhancement due to climate and atmospheric changes in British Colombia, Canada over 1956-2001.

PubMed

Wu, Chaoyang; Hember, Robbie A; Chen, Jing M; Kurz, Werner A; Price, David T; Boisvenue, Céline; Gonsamo, Alemu; Ju, Weimin

2014-03-25

Changes in climate and atmospheric CO2 and nitrogen (N) over the last several decades have induced significant effects on forest carbon (C) cycling. However, contributions of individual factors are largely unknown because of the lack of long observational data and the undifferentiating between intrinsic factors and external forces in current ecosystem models. Using over four decades (1956-2001) of forest inventory data at 3432 permanent samples in maritime and boreal regions of British Columbia (B.C.), Canada, growth enhancements were reconstructed and partitioned into contributions of climate, CO2 and N after removal of age effects. We found that climate change contributed a particularly large amount (over 70%) of the accumulated growth enhancement, while the remaining was attributed to CO2 and N, respectively. We suggest that climate warming is contributing a widespread growth enhancement in B.C.'s forests, but ecosystem models should consider CO2 and N fertilization effects to fully explain inventory-based observations.

Identifying ontogenetic, environmental and individual components of forest tree growth

PubMed Central

Chaubert-Pereira, Florence; Caraglio, Yves; Lavergne, Christian; Guédon, Yann

2009-01-01

Background and Aims This study aimed to identify and characterize the ontogenetic, environmental and individual components of forest tree growth. In the proposed approach, the tree growth data typically correspond to the retrospective measurement of annual shoot characteristics (e.g. length) along the trunk. Methods Dedicated statistical models (semi-Markov switching linear mixed models) were applied to data sets of Corsican pine and sessile oak. In the semi-Markov switching linear mixed models estimated from these data sets, the underlying semi-Markov chain represents both the succession of growth phases and their lengths, while the linear mixed models represent both the influence of climatic factors and the inter-individual heterogeneity within each growth phase. Key Results On the basis of these integrative statistical models, it is shown that growth phases are not only defined by average growth level but also by growth fluctuation amplitudes in response to climatic factors and inter-individual heterogeneity and that the individual tree status within the population may change between phases. Species plasticity affected the response to climatic factors while tree origin, sampling strategy and silvicultural interventions impacted inter-individual heterogeneity. Conclusions The transposition of the proposed integrative statistical modelling approach to cambial growth in relation to climatic factors and the study of the relationship between apical growth and cambial growth constitute the next steps in this research. PMID:19684021

Different radial growth responses of co-occurring coniferous forest trees in the Alps to drought

NASA Astrophysics Data System (ADS)

Oberhuber, Walter; Mennel, Julia

2010-05-01

Species-specific drought resistance will effect the development of forest ecosystems under a warmer and drier climate by changing species composition and inducing shifts in forest distribution. Therefore, we applied dendroclimatological techniques to determine drought sensitivity of three native coniferous tree species (Norway spruce, Picea abies; European larch, Larix decidua; Scots pine, Pinus sylvestris), which differ in phenological and successional traits and grow intermixed at dry-mesic sites within an inner-Alpine dry valley (750 m a.s.l., Tyrol, Austria). Ring-width chronologies (resolution 1 µm) of each species were developed by extracting two core samples from ≥ 80 mature trees (mean tree age 135 yr). To identify the climatic factors most closely associated with variations in radial tree growth, we calculated response and correlation functions for the common interval from 1911-2007 using yearly tree-ring indices and monthly and seasonal climate variables (precipitation, air temperature) and evaluated growth response to extreme hot and/or dry conditions during the growing season. Additionally, the impact of climate warming on long-term variability of climate-growth relationships was analysed by means of moving response functions. Major finding of our study were: (i) current April through June precipitation was the environmental factor most strongly associated with growth of all three species (r = 0.484, 0.458, and 0.546 for Pinus sylvestris, Larix decidua and Picea abies, respectively; all P < 0.001), whereby Picea abies showed higher correlation coefficients with precipitation from May through June (r = 0.585, P < 0.001). (ii) Annual increment of Picea abies was most strongly limited by May through June temperature (r = -0.500, P < 0.001). (iii) Continuously increasing moving response function coefficients of monthly precipitation variables since the mid-20th century revealed increasing drought sensitivity of all species. During recent decades a

Stimulating seedling growth in early stages of secondary forest succession: a modeling approach to guide tree liberation

PubMed Central

van Kuijk, Marijke; Anten, Niels P. R.; Oomen, Roelof J.; Schieving, Feike

2014-01-01

Excessive growth of non-woody plants and shrubs on degraded lands can strongly hamper tree growth and thus secondary forest succession. A common method to accelerate succession, called liberation, involves opening up the vegetation canopy around young target trees. This can increase growth of target trees by reducing competition for light with neighboring plants. However, liberation has not always had the desired effect, likely due to differences in light requirement between tree species. Here we present a 3D-model, which calculates photosynthetic rate of individual trees in a vegetation stand. It enables us to examine how stature, crown structure, and physiological traits of target trees and characteristics of the surrounding vegetation together determine effects of light on tree growth. The model was applied to a liberation experiment conducted with three pioneer species in a young secondary forest in Vietnam. Species responded differently to the treatment depending on their height, crown structure and their shade-tolerance level. Model simulations revealed practical thresholds over which the tree growth response is heavily influenced by the height and density of surrounding vegetation and gap radius. There were strong correlations between calculated photosynthetic rates and observed growth: the model was well able to predict growth of trees in young forests and the effects of liberation there upon. Thus, our model serves as a useful tool to analyze light competition between young trees and surrounding vegetation and may help assess the potential effect of tree liberation. PMID:25101100

Effects of stand age on the demography of a temperate forest herb in post-agricultural forests.

PubMed

Jacquemyn, Hans; Brys, Rein

2008-12-01

Changes in land use have been shown to have profound effects on forest plant community structure and diversity. Dispersal limitation has been invoked as a major factor hampering colonization of forest plant species, while seed-sowing experiments and performance observations have provided some evidence for recruitment limitation determining forest plant distribution in post-agricultural forests. However, most of these studies were relatively short-term, and very few studies have investigated long-term growth rates of populations occurring in recent and ancient forests. In this study, matrix models using demographic data collected for four consecutive years were used to study the effect of forest age on population dynamics of the temperate forest herb Primula elatior. A life table response experiment (LTRE) and elasticity analysis were used to analyze the effect of forest age on population growth rate (lambda) and to decompose the effect of forest age on lambda into contributions from each matrix element. Population growth increased logarithmically with increasing forest age. Bootstrap analyses showed that populations located in very recent forests (< 50-years-old) had growth rates that were significantly < 1, whereas populations located in forests > 150-years-old had growth rates that were significantly > 1. Summed elasticities for individual growth significantly decreased with increasing forest age, whereas summed elasticities for survival and fertility significantly increased with increasing forest age. The LTRE analysis showed that the increase in lambda with increasing forest age was mainly due to increased seedling and juvenile growth and increased juvenile and adult survival. Our results indicate that past agricultural land use has long-lasting effects on the demography of forest herbs and may provide an additional mechanistic explanation for the poor colonization capacity of many forest herbs in post-agricultural forests.

Patterns of mortality in an old-growth mixed-conifer forest of the Southern Sierra Nevada, California

Treesearch

Thomas F. Smith; David M. Rizzo; Malcolm North

2005-01-01

Mortality patterns in an old-growth, mixed-conifer forest, in the absence of wildfire, were investigated at the Teakettle Experimental Forest from 2000 to 2002. We tested the hypothesis that after a century of fire suppression, pathogen- and insect-associated mortality (between episodic droughts) would be significantly greater on ingrowth trees (i.e., smaller-diameter...

A synthesis of the science on forests and carbon for U.S. Forests

Treesearch

Michael G. Ryan; Mark E. Harmon; Richard A. Birdsey; Christian P. Giardina; Linda S. Heath; Richard A. Houghton; Robert B. Jackson; Duncan C. McKinley; James F. Morrison; Brian C. Murray; Diane E. Pataki; Kenneth E. Skog

2010-01-01

Forests play an important role in the U.S. and global carbon cycle, and carbon sequestered by U.S. forest growth and harvested wood products currently offsets 12-19% of U.S. fossil fuel emissions. The cycle of forest growth, death, and regeneration and the use of wood removed from the forest complicate efforts to understand and measure forest carbon pools and flows....

Growth strategies and threshold responses to water deficit modulate effects of warming on tree seedlings from forest to alpine

USGS Publications Warehouse

Lazarus, Brynne E.; Castanha, Cristina; Germino, Matthew; Kueppers, Lara M.; Moyes, Andrew B.

2018-01-01

1.Predictions of upslope range shifts for tree species with warming are based on assumptions of moisture stress at lower elevation limits and low temperature stress at high elevation limits. However, recent studies have shown that warming can reduce tree seedling establishment across the entire gradient from subalpine forest to alpine via moisture limitation. Warming effects also vary with species, potentially resulting in community shifts in high elevation forests. 2.We examined the growth and physiology underlying effects of warming on seedling demographic patterns. We evaluated dry mass (DM), root length, allocation above- and belowground, and relative growth rate (RGR) of whole seedlings, and their ability to avoid or endure water stress via water-use efficiency and resisting turgor loss, for Pinus flexilis, Picea engelmannii and Pinus contorta seeded below, at, and above treeline in experimentally warmed, watered, and control plots in the Rocky Mountains, USA. We expected that growth and allocation responses to warming would relate to moisture status and that variation in drought tolerance traits would explain species differences in survival rates. 3.Across treatments and elevations, seedlings of all species had weak turgor-loss resistance, and growth was marginal with negative RGR in the first growth phase (-0.01 to -0.04 g/g/d). Growth was correlated with soil moisture, particularly in the relatively small-seeded P. contorta and P. engelmannii. P. flexilis, known to have the highest survivorship, attained the greatest DM and longest root but was also the slowest growing and most water-use-efficient. This was likely due to its greater reliance on seed reserves. Seedlings developed 15% less total DM, 25% less root DM, and 11% shorter roots in heated compared to unheated plots. Higher temperatures slightly increased DM, root length and RGR where soils were wettest, but more strongly decreased these variables under drier conditions. 4.Synthesis: The surprising

Measured and modeled evidence for a two-fold increase in water use efficiency at an old-growth forest site in the Pacific Northwest

NASA Astrophysics Data System (ADS)

Jiang, Y.; Rastogi, B.; Kim, J. B.; Voelker, S.; Meinzer, F. C.; Still, C. J.

2017-12-01

Water use efficiency (WUE), the ratio of carbon uptake to transpiration, has been widely recognized as an important measure of carbon and water cycling in plants, and is used to track forest ecosystem responses to climate change and rising atmospheric CO2concentrations. In this study we used eddy covariance measurement data and Ecosystem Demography model (ED2) simulations to explore the patterns and physiological and biophysical controls of WUE at Wind River Experimental Forest, an old-growth coniferous forest in the Pacific Northwest. We characterized how observed and simulated WUE vary between wet and dry years, and explored the drivers of the differences in WUE between the wet and dry years. Through this explorative process, we evaluated the utility of various ways that WUE have been computed in literature. Measurement-based and simulated WUE at the old-growth forest increased over twofold from 1998 to 2015. The primary driver of this trend is a decreasing trend in evapotranspiration (ET). There were significant inter-annual variations. For example, during drought years, higher air temperature drove increases in early season ET, thereby depleting soil water and decreasing GPP. Lower GPP in turn resulted in lower WUE. This mechanism might drive changes in future carbon and water budgets under warming climate. Our evaluation of multiple WUE metrics demonstrates that each metric has a distinct sensitivity to climate anomalies, but also indicates a robust increasing trend of WUE. Statistical (multiple linear regression) and machine learning (Random Forest) analyses of flux measurements indicated that atmospheric CO2 concentration, air temperature and radiation were the most important predictors of WUE at monthly, daily and half-hourly time scale, respectively. In contrast, WUE mechanism was stable across all time scales in ED2 simulations: vapor pressure deficit was consistently the most important predictor of WUE at the monthly, daily and half-hourly time scales.

Disparate effects of global-change drivers on mountain conifer forests: warming-induced growth enhancement in young trees vs. CO2 fertilization in old trees from wet sites.

PubMed

Camarero, J Julio; Gazol, Antonio; Galván, Juan Diego; Sangüesa-Barreda, Gabriel; Gutiérrez, Emilia

2015-02-01

Theory predicts that the postindustrial rise in the concentration of CO2 in the atmosphere (c(a)) should enhance tree growth either through a direct fertilization effect or indirectly by improving water use efficiency in dry areas. However, this hypothesis has received little support in cold-limited and subalpine forests where positive growth responses to either rising ca or warmer temperatures are still under debate. In this study, we address this issue by analyzing an extensive dendrochronological network of high-elevation Pinus uncinata forests in Spain (28 sites, 544 trees) encompassing the whole biogeographical extent of the species. We determine if the basal area increment (BAI) trends are linked to climate warming and increased c(a) by focusing on region- and age-dependent responses. The largest improvement in BAI over the past six centuries occurred during the last 150 years affecting young trees and being driven by recent warming. Indeed, most studied regions and age classes presented BAI patterns mainly controlled by temperature trends, while growing-season precipitation was only relevant in the driest sites. Growth enhancement was linked to rising ca in mature (151-300 year-old trees) and old-mature trees (301-450 year-old trees) from the wettest sites only. This finding implies that any potential fertilization effect of elevated c(a) on forest growth is contingent on tree features that vary with ontogeny and it depends on site conditions (for instance water availability). Furthermore, we found widespread growth decline in drought-prone sites probably indicating that the rise in ca did not compensate for the reduction in water availability. Thus, warming-triggered drought stress may become a more important direct driver of growth than rising ca in similar subalpine forests. We argue that broad approaches in biogeographical and temporal terms are required to adequately evaluate any effect of rising c(a) on forest growth. © 2014 John Wiley & Sons Ltd.

Xylem traits, leaf longevity and growth phenology predict growth and mortality response to defoliation in northern temperate forests.

PubMed

Foster, Jane R

2017-09-01

Defoliation outbreaks are biological disturbances that alter tree growth and mortality in temperate forests. Trees respond to defoliation in many ways; some recover rapidly, while others decline gradually or die. Functional traits such as xylem anatomy, growth phenology or non-structural carbohydrate (NSC) storage could explain these responses, but idiosyncratic measures used by defoliation studies have frustrated efforts to generalize among species. Here, I test for functional differences with published growth and mortality data from 37 studies, including 24 tree species and 11 defoliators from North America and Eurasia. I synthesized data into standardized variables suitable for numerical models and used linear mixed-effects models to test the hypotheses that responses to defoliation vary among species and functional groups. Standardized data show that defoliation responses vary in shape and degree. Growth decreased linearly or curvilinearly, least in ring-porous Quercus and deciduous conifers (by 10-40% per 100% defoliation), whereas growth of diffuse-porous hardwoods and evergreen conifers declined by 40-100%. Mortality increased exponentially with defoliation, most rapidly for evergreen conifers, then diffuse-porous, then ring-porous species and deciduous conifers (Larix). Goodness-of-fit for functional-group models was strong (R2c = 0.61-0.88), if lower than species-specific mixed-models (R2c = 0.77-0.93), providing useful alternatives when species data are lacking. These responses are consistent with functional differences in leaf longevity, wood growth phenology and NSC storage. When defoliator activity lags behind wood-growth, either because xylem-growth precedes budburst (Quercus) or defoliator activity peaks later (sawflies on Larix), impacts on annual wood-growth will always be lower. Wood-growth phenology of diffuse-porous species and evergreen conifers coincides with defoliation and responds more drastically, and lower axial NSC storage makes them

Managing heart rot in live trees for wildlife habitat in young-growth forests of coastal Alaska

Treesearch

Paul E. Hennon; Robin L. Mulvey

2014-01-01

Stem decays of living trees, known also as heart rots, are essential elements of wildlife habitat, especially for cavity-nesting birds and mammals. Stem decays are common features of old-growth forests of coastal Alaska, but are generally absent in young, managed forests. We offer several strategies for maintaining or restoring fungal stem decay in these managed...

Notes on Some Old-Growth Forests in Ohio, Indiana, and Illinois

Treesearch

John T. Auten

1941-01-01

The disturbing increase in acreage of abandoned land in the Central States has heightened interest in the region's few remnants of old-growth hardwood forest. Studies are being made to determine what kinds of trees originally grew on different kinds of soil, what was the original character of the soil, how many trees grew on an acre, and how large the trees were...

Ground cover in old-growth forests of the central hardwood region

Treesearch

Martin A. Spetich; Stephen R. Shifley; George R. Parker; Felix, Jr. Ponder

1997-01-01

Differences in ground cover (percent cover of litter, percent cover of vegetation and litter weight) in old-growth forests across this region are not well understood. We initiated a long-term study in a three-state region to enhance knowledge in this area. We present baseline results for ground cover and compare these data across productivity regions. Thirty 0.25-ac (0...

The Effect of Herbivory by White-Tailed Deer and Additionally Swamp Rabbits in an Old-Growth Bottomland Hardwood Forest

Treesearch

Margaret S. Devall; Bernard R. Parresol; Winston P. Smith

2001-01-01

Forest openings create internal patchiness and offer different habitat qualities that attract wildlife, especially herbivores, that flourish along forest edges. But intense herbivory in these openings can reduce or eliminate herbaceous and woody species and thus influence local species composition and structure of the forest. This study in an old-growth bottomland...

Winter drought impairs xylem phenology, anatomy and growth in Mediterranean Scots pine forests.

PubMed

Camarero, J J; Guada, G; Sánchez-Salguero, R; Cervantes, E

2016-12-01

Continental Mediterranean forests face drought but also cold spells and both climate extremes can impair the resilience capacity of these forests. Climate warming could amplify the negative effects of cold spells by inducing premature dehardening. Here we capitalize on a winter drought-induced dieback triggered by a cold spell which occurred in December 2001 affecting Scots pine forests in eastern Spain. We assessed post-dieback recovery by quantifying and comparing radial growth and xylem anatomy of non-declining (ND, crown cover >50%) and declining (D, crown cover ≤50%) trees in two sites (VP, Villarroya de los Pinares; TO, Torrijas). We also characterized xylogenesis in both sites and aboveground productivity in site VP. Dieback caused legacy effects since needle loss, a 60% reduction in litter fall and radial-growth decline characterized D-trees 3 years after dieback symptoms started appearing in spring 2002. D-trees formed collapsed tracheids in the 2002-ring, particularly in the most affected VP site where xylogenesis differences between ND and D trees were most noticeable. The lower growth rates of D-trees were caused by a shorter duration of their major xylogenesis phases. In site VP the radial-enlargement and wall-thickening of tracheids were significantly reduced in D-trees as compared to ND-trees because these xylogenesis phases tended to start earlier and end later in ND-trees. Gompertz models fitted to tracheid production predicted that maximum growth rates occurred 11-12 days earlier in ND than in D-trees. The formation of radially-enlarging tracheids was enhanced by longer days in both study sites and also by wetter conditions in the driest TO site, but xylogenesis sensitivity to climate was reduced in D-trees. Winter-drought dieback impairs xylem anatomy and phenology, aboveground productivity, xylogenesis and growth in Mediterranean Scots pine populations. Affected stands show a costly post-dieback recovery challenging their resilience ability

Emergy and Eco-exergy Evaluation of Four Forest Restoration Modes

EPA Science Inventory

Four different forest restoration modes (Acacia mangium plantation, mixed-native species plantation, conifer plantation and Eucalyptus plantation) were evaluated using Energy System Theory and the emergy synthesis method. In addition, the eco-exergies of the four forest restorati...

Preliminary Survey on TRY Forest Traits and Growth Index Relations - New Challenges

NASA Astrophysics Data System (ADS)

Lyubenova, Mariyana; Kattge, Jens; van Bodegom, Peter; Chikalanov, Alexandre; Popova, Silvia; Zlateva, Plamena; Peteva, Simona

2016-04-01

Forest ecosystems provide critical ecosystem goods and services, including food, fodder, water, shelter, nutrient cycling, and cultural and recreational value. Forests also store carbon, provide habitat for a wide range of species and help alleviate land degradation and desertification. Thus they have a potentially significant role to play in climate change adaptation planning through maintaining ecosystem services and providing livelihood options. Therefore the study of forest traits is such an important issue not just for individual countries but for the planet as a whole. We need to know what functional relations between forest traits exactly can express TRY data base and haw it will be significant for the global modeling and IPBES. The study of the biodiversity characteristics at all levels and functional links between them is extremely important for the selection of key indicators for assessing biodiversity and ecosystem services for sustainable natural capital control. By comparing the available information in tree data bases: TRY, ITR (International Tree Ring) and SP-PAM the 42 tree species are selected for the traits analyses. The dependence between location characteristics (latitude, longitude, altitude, annual precipitation, annual temperature and soil type) and forest traits (specific leaf area, leaf weight ratio, wood density and growth index) is studied by by multiply regression analyses (RDA) using the statistical software package Canoco 4.5. The Pearson correlation coefficient (measure of linear correlation), Kendal rank correlation coefficient (non parametric measure of statistical dependence) and Spearman correlation coefficient (monotonic function relationship between two variables) are calculated for each pair of variables (indexes) and species. After analysis of above mentioned correlation coefficients the dimensional linear regression models, multidimensional linear and nonlinear regression models and multidimensional neural networks models are

Effects of tree size and spatial distribution on growth of ponderosa pine forests under alternative management scenarios

Treesearch

C.W. Woodall; C.E. Fiedler; R.E. McRoberts

2009-01-01

Forest ecosystems may be actively managed toward heterogeneous stand structures to provide both economic (e.g., wood production and carbon credits) and environmental benefits (e.g., invasive pest resistance). In order to facilitate wider adoption of possibly more sustainable forest stand structures, defining growth expectations among alternative management scenarios is...

Evaluating the ecological trade-offs of riparian thinning for headwater stream ecosystems in second-growth redwood forests

Treesearch

David Roon; Jason Dunham; Bret Harvey; Ryan Bellmore; Deanna Olson; Gordon Reeves

2017-01-01

After decades of intensive timber harvest and land use change that removed forests from the landscape, recent satellite data show that forest cover has increased in North America (Liu et al. 2015). However, these regenerating forests differ greatly in structure and composition than the forests that preceded them (McIntyre et al. 2015). This has been especially evident...

Texas' forests, 2008

Treesearch

James W. Bentley; Consuelo Brandeis; Jason A. Cooper; Christopher M. Oswalt; Sonja N. Oswalt; KaDonna Randolph

2014-01-01

This bulletin describes forest resources of the State of Texas at the time of the 2008 forest inventory. This bulletin addresses forest area, volume, growth, removals, mortality, forest health, timber product output, and the economy of the forest sector.

Candidate old-growth on national forest system administered lands in California since the initiation of national forest management

Treesearch

William F. Laudenslayer

1985-01-01

The following is a report on the status of Candidate Old-growth (hereafter identified as COG) on National Forest System administered lands in California in the past, a t present, and in the immediate fhture. These r e s u l t s are based on information that may be speculative and contain inconsistencies, and therefore must be treated with caution. COG on these lands...

Evaluation of forest snow processes models (SnowMKIP2)

Treesearch

Nick Rutter; Richard Essery; John Pomeroy; Nuria Altimir; Kostas Andreadis; Ian Baker; Alan Barr; Paul Bartlett; Aaron Boone; Huiping Deng; Herve Douville; Emanuel Dutra; Kelly Elder; others

2009-01-01

Thirty-three snowpack models of varying complexity and purpose were evaluated across a wide range of hydrometeorological and forest canopy conditions at five Northern Hemisphere locations, for up to two winter snow seasons. Modeled estimates of snow water equivalent (SWE) or depth were compared to observations at forest and open sites at each location. Precipitation...

Using US Forest Inventory (FIA) Data to Test for Growth Enhancement

NASA Astrophysics Data System (ADS)

Masek, J. G.; Collatz, G. J.; Williams, C. A.

2015-12-01

It is recognized that land ecosystems sequester a significant fraction of anthropogenic carbon emissions, and that the magnitude of the "land sink" appears to be increasing through time. This observation has led to the hypothesis that forest ecosystems are experiencing more rapid growth than their historical norm, due to some combination of CO2 fertilization, longer growing seasons, nitrogen deposition, and more intensive management. Direct evidence for growth enhancment has been reported from experimental plots, where long-term (historical) rates of biomass accumulation appear lower than contemporary rates derived from remeasurement of individual trees. However, the approach has not been pursued at a national scale. Since the late 1990's the US Forest Inventory and Analysis (FIA) program has standardized plot locations across the United States, and has systematically remeasured tree and plot attributes on 5-year (east) or 10-year (west) cycles. In principle, these remeasured plots provide a robust dataset for comparing contemporary and historical growth rates. In this talk we review approaches for performing this comparison at both plot and tree scales. We find that recent plot-level biomass accumulation rates from the eastern US do show more rapid growth than would be expected from historical biomass-age curves, with enhancement factors of up 2x. However, the implicit inclusion of "cryptic" or older disturbances in the historical curves hinders a definitive interpretation. Stand-level age-biomass simulations confirm that disturbance events must be included in the remeasured data set in order to provide comparability with historical curves. Remeasured DBH measurements from individual trees may provide a more robust approach for examining the issue.

A synthesis of evaluation monitoring projects by the forest health monitoring program (1998-2007)

Treesearch

William A. Bechtold; Michael J. Bohne; Barbara L. Conkling; Dana L. Friedman

2012-01-01

The national Forest Health Monitoring Program of the Forest Service, U.S. Department of Agriculture, has funded over 200 Evaluation Monitoring projects. Evaluation Monitoring is designed to verify and define the extent of deterioration in forest ecosystems where potential problems have been identified. This report is a synthesis of results from over 150 Evaluation...

Reduced aboveground tree growth associated with higher arbuscular mycorrhizal fungal diversity in tropical forest restoration.

PubMed

Holste, Ellen K; Holl, Karen D; Zahawi, Rakan A; Kobe, Richard K

2016-10-01

Establishing diverse mycorrhizal fungal communities is considered important for forest recovery, yet mycorrhizae may have complex effects on tree growth depending on the composition of fungal species present. In an effort to understand the role of mycorrhizal fungi community in forest restoration in southern Costa Rica, we sampled the arbuscular mycorrhizal fungal (AMF) community across eight sites that were planted with the same species ( Inga edulis, Erythrina poeppigiana, Terminalia amazonia, and Vochysia guatemalensis ) but varied twofold to fourfold in overall tree growth rates. The AMF community was measured in multiple ways: as percent colonization of host tree roots, by DNA isolation of the fungal species associated with the roots, and through spore density, volume, and identity in both the wet and dry seasons. Consistent with prior tropical restoration research, the majority of fungal species belonged to the genus Glomus and genus Acaulospora , accounting for more than half of the species and relative abundance found on trees roots and over 95% of spore density across all sites. Greater AMF diversity correlated with lower soil organic matter, carbon, and nitrogen concentrations and longer durations of prior pasture use across sites. Contrary to previous literature findings, AMF species diversity and spore densities were inversely related to tree growth, which may have arisen from trees facultatively increasing their associations with AMF in lower soil fertility sites. Changes to AMF community composition also may have led to variation in disturbance susceptibility, host tree nutrient acquisition, and tree growth. These results highlight the potential importance of fungal-tree-soil interactions in forest recovery and suggest that fungal community dynamics could have important implications for tree growth in disturbed soils.

Possibilities and limitations of using historic provenance tests to infer forest species growth responses to climate change

Treesearch

Laura P. Leites; Gerald E. Rehfeldt; Andrew P. Robinson; Nicholas L. Crookston; Barry Jaquish

2012-01-01

Under projected changes in global climate, the growth and survival of existing forests will depend on their ability to adjust physiologically in response to environmental change. Quantifying their capacity to adjust and whether the response is species- or population-specific is important to guide forest management strategies. New analyses of historic provenance tests...

Coarse Woody Debris Ecology in a Second-Growth Sequoia sempervirens Forest Stream

Treesearch

Matthew D. O' Connor; Robert R. Ziemer

1989-01-01

Coarse woody debris (CWD) contributes to high quality habitat for anadromous fish. CWD volume, species, and input mechanisms was inventoried in North Fork Caspar Creek to assess rates of accumulation and dominant sources of CWD in a 100-year-old second-growth redwood (Sequoia sempervirens) forest. CWD accumulation in the active stream channel and in...

Grow--a computer subroutine that projects the growth of trees in the Lake States' forests.

Treesearch

Gary J. Brand

1981-01-01

A computer subroutine, Grow, has been written in 1977 Standard FORTRAN to implement a distance-independent, individual tree growth model for Lake States' forests. Grow is a small and easy-to-use version of the growth model. All the user has to do is write a calling program to read initial conditions, call Grow, and summarize the results.

Windthrow and salvage logging in an old-growth hemlock-northern hardwoods forest

USGS Publications Warehouse

Lang, K.D.; Schulte, L.A.; Guntenspergen, G.R.

2009-01-01

Although the initial response to salvage (also known as, post-disturbance or sanitary) logging is known to vary among system components, little is known about longer term forest recovery. We examine forest overstory, understory, soil, and microtopographic response 25 years after a 1977 severe wind disturbance on the Flambeau River State Forest in Wisconsin, USA, a portion of which was salvage logged. Within this former old-growth hemlock-northern hardwoods forest, tree dominance has shifted from Eastern hemlock (Tsuga canadensis) to broad-leaf deciduous species (Ulmus americana, Acer saccharum, Tilia americana, Populus tremuloides, and Betula alleghaniensis) in both the salvaged and unsalvaged areas. While the biological legacies of pre-disturbance seedlings, saplings, and mature trees were initially more abundant in the unsalvaged area, regeneration through root suckers and stump sprouts was common in both areas. After 25 years, tree basal area, sapling density, shrub layer density, and seedling cover had converged between unsalvaged and salvaged areas. In contrast, understory herb communities differed between salvaged and unsalvaged forest, with salvaged forest containing significantly higher understory herb richness and cover, and greater dominance of species benefiting from disturbance, especially Solidago species. Soil bulk density, pH, organic carbon content, and organic nitrogen content were also significantly higher in the salvaged area. The structural legacy of tip-up microtopography remains more pronounced in the unsalvaged area, with significantly taller tip-up mounds and deeper pits. Mosses and some forest herbs, including Athyrium filix-femina and Hydrophyllum virginianum, showed strong positive responses to this tip-up microrelief, highlighting the importance of these structural legacies for understory biodiversity. In sum, although the pathways of recovery differed, this forest appeared to be as resilient to the compound disturbances of windthrow

Late-successional forests and northern spotted owls: how effective is the Northwest Forest Plan?

Treesearch

Miles Hemstrom; Martin G. Raphael

2000-01-01

This paper describes the late-successional and old-growth forest and the northern spotted owl effectiveness monitoring plans for the Northwest Forest Plan. The effectiveness monitoring plan for late-successional and old-growth forests will track changes in forest spatial distribution, and within-stand structure and composition, and it will predict future trends.

The forest resources of the Ottawa National Forest, 1993.

Treesearch

Earl C. Leatherberry; James L. Meunier

1997-01-01

The inventory of the forest resources of the Ottawa National Forest reports 967.0 thousand acres of land, of which 908.6 thousand acres are forested. This bulletin presents an analysis of forest resources focusing on change in tree species composition, timber volume, growth, removals, and mortality.

Coarse woody debris ecology in a second-growth Sequoia sempervirens forest stream

Treesearch

Matthew D. O' Connor; Robert R. Ziemer

1989-01-01

Abstract - Coarse woody debris (CWD) contributes to high quality habitat for anadromous fish. CWD volume, species, and input mechanisms was inventoried in North Fork Caspar Creek to assess rates of accumulation and dominant sources of CWD in a 100-year-old second-growth redwood (Sequoia sempervirens) forest. CWD accumulation in the active stream channel and in pools...

The potential for species conservation in tropical secondary forests.

PubMed

Chazdon, Robin L; Peres, Carlos A; Dent, Daisy; Sheil, Douglas; Lugo, Ariel E; Lamb, David; Stork, Nigel E; Miller, Scott E

2009-12-01

In the wake of widespread loss of old-growth forests throughout the tropics, secondary forests will likely play a growing role in the conservation of forest biodiversity. We considered a complex hierarchy of factors that interact in space and time to determine the conservation potential of tropical secondary forests. Beyond the characteristics of local forest patches, spatial and temporal landscape dynamics influence the establishment, species composition, and persistence of secondary forests. Prospects for conservation of old-growth species in secondary forests are maximized in regions where the ratio of secondary to old-growth forest area is relatively low, older secondary forests have persisted, anthropogenic disturbance after abandonment is relatively low, seed-dispersing fauna are present, and old-growth forests are close to abandoned sites. The conservation value of a secondary forest is expected to increase over time, as species arriving from remaining old-growth forest patches accumulate. Many studies are poorly replicated, which limits robust assessments of the number and abundance of old-growth species present in secondary forests. Older secondary forests are not often studied and few long-term studies are conducted in secondary forests. Available data indicate that both old-growth and second-growth forests are important to the persistence of forest species in tropical, human-modified landscapes.

Forest resources of the Hoosier National Forest, 2005

Treesearch

Christoper W. Woodall; Judith A. Perez; Thomas R. Thake

2007-01-01

The first annual inventory of the Hoosier National Forest reports more than 200,000 forest land acres dominated by oaks, maples, and hickories with annual growth exceeding annual mortality by a factor of seven. When compared to forests in the rest of Indiana, the Hoosier's forests are on average older, have greater biomass per acre, and possess a greater...

Tree species and size structure of old-growth Douglas-fir forests in central western Oregon, USA

USGS Publications Warehouse

Poage, Nathan; Tappeiner, J. C.

2005-01-01

We characterized the structure of 91 old-growth forests dominated by Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), using inventory data from recent (1985a??1991) old-growth timber sales in western Oregon. The data were complete counts (i.e., censuses) of all live trees >20 cm diameter at breast height (dbh, measured at 1.4 m above the ground) over a mean area of 17.1 ha at each site. Across all sites, Douglas-fir accounted for 79% of the total basal area (m2/ha) of all species. The average density of trees >100 cm dbh was 19 trees/ha and 90% of these trees were Douglas-fir. Species other than Douglas-fir constituted only about 20% of the total basal area at each old-growth site, on average, but largely accounted for the structural variation between sites. We used multivariate techniques such as cluster analysis, indicator species analysis, and ordination with non-metric multidimensional scaling (NMS) to identify and characterize six structural groups in terms of basal area in different speciesa??diameter classes. Almost 97% of the structural information was captured by the first (r2 = 0.841) and second (r2 = 0.128) NMS ordination axis. Geographic information systems (GIS) analysis and NMS indicated that the structural differences among groups of sites were associated with moisture, temperature, and elevation gradients within the study area. This type of analysis can be used to help define differences among old-growth forests and to set local structural goals for growing forests with old-growth characteristics.

Determining successional stage of temperate coniferous forests with Landsat satellite data

NASA Technical Reports Server (NTRS)

Fiorella, Maria; Ripple, William J.

1995-01-01

Thematic Mapper (TM) digital imagery was used to map forest successional stages and to evaluate spectral differences between old-growth and mature forests in the central Cascade Range of Oregon. Relative sun incidence values were incorporated into the successional stage classification to compensate for topographic induced variation. Relative sun incidence improved the classification accuracy of young successional stages, but did not improve the classification accuracy of older, closed canopy forest classes or overall accuracy. TM bands 1, 2, and 4; the normalized difference vegetation index (NDVI); and TM 4/3, 4/5, and 4/7 band ratio values for old-growth forests were found to be significantly lower than the values of mature forests (P less than or equal to 0.010). Wetness and the TM 4/5 and 4/7 band ratios all had low correlations to relative sun incidence (r(exp 2) less than or equal to 0.16). The TM 4/5 band ratio was named the 'structural index' (SI) because of its ability to distinguish between mature and old-growth forests and its simplicity.

Effects of soil compaction on residual stand growth in central Appalachian hardwood forest: a preliminary case study

Treesearch

Jingxin Wang; Chris LeDoux; Michael Vanderberg; Li Yaoxiang

2006-01-01

A preliminary study that quantified the impacts of soil compaction on residual tree growth associated with ground-based skidding traffic intensity and turn payload size was investigated in the central Appalachian hardwood forest. The field study was carried out on a 20-acre tract of the West Virginia University Research Forest. Skid trails were laid out in 170' -...

An eco-efficient and economical optimum evaluation technique for the forest road networks: the case of the mountainous forest of Metsovo, Greece.

PubMed

Tampekis, Stergios; Samara, Fani; Sakellariou, Stavros; Sfougaris, Athanassios; Christopoulou, Olga

2018-02-12

The sustainable forest management can be achieved only through environmentally sound and economically efficient and feasible forest road networks and transportation systems that can potentially improve the multi-functional use of forest resources. However, road network planning and construction suggest long-term finance that require a capital investment (cash outflow), which would be equal to the value of the total revenue flow (cash inflow) over the whole lifecycle project. This paper emphasizes in an eco-efficient and economical optimum evaluation method for the forest road networks in the mountainous forest of Metsovo, Greece. More specifically, with the use of this technique, we evaluated the forest roads' (a) total construction costs, (b) annual maintenance cost, and (c) log skidding cost. In addition, we estimated the total economic value of forest goods and services that are lost from the forest roads' construction. Finally, we assessed the optimum eco-efficient and economical forest roads densities based on linear equations that stem from the internal rate of return method (IRR) and have been presented graphically. Data analysis and its presentation are achieved with the contribution of geographic information systems (GIS). The technique which is described in this study can be for the decision makers an attractive and useful implement in order to select the most eco-friendly and economical optimum solution to plan forest road network or to evaluate the existing forest transportation systems. Hence, with the use of this method, we can combine not only the multi-objective utilization of natural resources but also the environmental protection of forest ecosystems.

Response of Quercus velutina growth and water use efficiency to climate variability and nitrogen fertilization in a temperate deciduous forest in the northeastern USA.

PubMed

Jennings, Katie A; Guerrieri, Rossella; Vadeboncoeur, Matthew A; Asbjornsen, Heidi

2016-04-01

Nitrogen (N) deposition and changing climate patterns in the northeastern USA can influence forest productivity through effects on plant nutrient relations and water use. This study evaluates the combined effects of N fertilization, climate and rising atmospheric CO2on tree growth and ecophysiology in a temperate deciduous forest. Tree ring widths and stable carbon (δ(13)C) and oxygen (δ(18)O) isotopes were used to assess tree growth (basal area increment, BAI) and intrinsic water use efficiency (iWUE) ofQuercus velutinaLamb., the dominant tree species in a 20+ year N fertilization experiment at Harvard Forest (MA, USA). We found that fertilized trees exhibited a pronounced and sustained growth enhancement relative to control trees, with the low- and high-N treatments responding similarly. All treatments exhibited improved iWUE over the study period (1984-2011). Intrinsic water use efficiency trends in the control trees were primarily driven by changes in stomatal conductance, while a stimulation in photosynthesis, supported by an increase in foliar %N, contributed to enhancing iWUE in fertilized trees. All treatments were predominantly influenced by growing season vapor pressure deficit (VPD), with BAI responding most strongly to early season VPD and iWUE responding most strongly to late season VPD. Nitrogen fertilization increasedQ. velutinasensitivity to July temperature and precipitation. Combined, these results suggest that ambient N deposition in N-limited northeastern US forests has enhanced tree growth over the past 30 years, while rising ambient CO2has improved iWUE, with N fertilization and CO2having synergistic effects on iWUE. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Forest ecosystem service and its evaluation in China].

PubMed

Fang, Jin; Lu, Shaowei; Yu, Xinxiao; Rao, Liangyi; Niu, Jianzhi; Xie, Yuanyuan; Zhag, Zhenming

2005-08-01

Facing the relative lag of forest ecosystem service and estimation in China, this paper proposed to quickly carry out the research on the evaluation of forest ecosystem service. On the basis of the classification of forest ecosystem types in China, the service of artificial and semi-artificial forest ecosystems was investigated, which was divided into eight types, i.e., timber and other products, recreation and eco-tourism, water storage, C fixation and O2 release, nutrient cycling, air quality purifying, erosion control, and habitat provision. According to the assessment index system for global ecosystem service proposed by Costanza et al., a series of assessment index system suitable for Chinese forest ecosystem service was set up, by which, the total value of forest ecosystem service in China was estimated to be 30 601.20 x 10(8) yuan x yr(-1), including direct and indirect economic value about 1 920.23 x 10(8) and 28 680.97 x 10(8) yuan x yr(-1), respectively. The indirect value was as 14.94 times as the direct one. The research aimed to bring natural resources and environment factors into the account system of national economy quickly, and to realize the green GDP at last, which would be helpful to realize sustainable development and environment protection.

[Evapotranspiration characteristics of artificial and natural forests in Liupan Mountains of Ningxia, China during growth season].

PubMed

Cao, Gong-xiang; Wang, Xu-fang; Xiong, Wei; Wang, Yan-hui; Yu, Peng-tao; Wang, Yun-ni; Xu, Li-hong; Li, Zhen-hua

2013-08-01

In order to understand the effects of the structure of forest ecosystem on the hydrological processes, a comparative study by using thermal dissipation technique and hydrological methodology was made on the evapotranspiration (ET) and its components of Larix principis-rupprechtii plantation and Pinus armandi natural forest in two adjacent stands in a small catchment Xiangshuihe of Liupan Mountains during the growth season (May-October) in 2009. Throughout the growth season, the total ET from the plantation was 518.2 mm, which accounted for 104.6% of the precipitation and was much higher than that (420.5 mm) of the natural forest. The allocation of ET in the vertical layers performed similarly between the two stands, with the order of canopy layer > herb and soil layer > shrub layer, but the ratio of each component to total ET differed significantly. The plantation consumed 0.2 and 0.9 times more water for canopy interception (19.6 mm per month) and tree transpiration (25.2 mm per month) than the natural forest, respectively. However, the transpiration from the plantation was 4.4 mm per month, and took up 23.4% of the natural forest. In contrast, the sum of soil evaporation and herbage evapotranspiration consumed 37.1 mm water per month in the plantation, which was 0.8 times higher than that in the natural forest. The ET was calculated by Penman-Monteith equation to compare the results estimated by sap flow measurements, and the values estimated by the two methods were similar.

Tree growth rates in an Amazonian evergreen forest: seasonal patterns and correlations with leaf phenology

NASA Astrophysics Data System (ADS)

Wu, J.; Silva Campos, K.; Prohaska, N.; Ferreira, M. L.; Nelson, B. W.; Saleska, S. R.; da Silva, R.

2014-12-01

Metabolism and phenology of tropical forests significantly influence global dynamics of climate, carbon and water. However, there is still lack of mechanistic understanding of the controls on tropical forest metabolism, particularly at individual tree level. In this study, we are interested in investigating (1) what is the seasonal pattern of woody growth for tropical trees and (2) what is the mechanistic controls onwoody growth at individual level?To explore the above questions,we use two data sources from an evergreen tropical forest KM67 site (near Santarem, Brazil). They are: (1) image time series from a tower mounted RGB imaging system, with images recordedin10 minutes interval since October 2013.Images near local noon homogeneous diffuse lighting were selectedfor leaf phenologymonitoring; (2) ground based bi-weekly biometry survey (via dendrometry band technique) for 25 trees from random sampling since September 2013. 12 among 25 trees are within the tower mounted camera image view. Our preliminary resultsdemonstrate that 20 trees among 25 trees surveyed significantly increase woody growth (or "green up") in dry season. Our results also find thatamong those 20 trees, 12 trees reaches the maximum woody increment rate in late dry season with a mean DBH (Diameter at Breast Height) around 30 cm,while 8 trees reaching the maximum in the middle of wet season, with a mean DBH around 90 cm. This study,though limited in the sample size, mightprovide another line of evidence that Amazon rainforests "green up" in dry season. As for mechanistic controls on tropical tree woody control, we hypothesize both climate and leaf phenology control individual woody growth. We would like to link both camera based leaf phenology and climate data in the next to explorethe reason as to the pattern found in this study that bigger trees might have different seasonal growth pattern as smaller trees.

Forests of the Black Hills National Forest 2011

Treesearch

Brian F. Walters; Christopher W. Woodall; Ronald J. Piva; Mark A. Hatfield; Grant M. Domke; David E. Haugen

2013-01-01

This inventory of the Black Hills National Forest (BHNF) covers the years 2007-2011 on the South Dakota portion of the forest and 2005 on the Wyoming portion. It reports more than 1.16 million acres of forest land dominated by ponderosa pine. Forest features reported on include volume, biomass, growth, removals, mortality, carbon, snags, and down woody material, along...

Evaluating the Suitability of Management Strategies of Pure Norway Spruce Forests in the Black Forest Area of Southwest Germany for Adaptation to or Mitigation of Climate Change

NASA Astrophysics Data System (ADS)

Yousefpour, Rasoul; Hanewinkel, Marc; Le Moguédec, Gilles

2010-02-01

The study deals with the problem of evaluating management strategies for pure stands of Norway spruce ( Picea abies Karst) to balance adaptation to and mitigation of climate change, taking into account multiple objectives of a forest owner. A simulation and optimization approach was used to evaluate the management of a 1000 ha model Age-Class forest, representing the age-class distribution of an area of 66,000 ha of pure Norway spruce forests in the Black Forest region of Southwest Germany. Eight silvicultural scenarios comprising five forest conversion schemes which were interpreted as “adaptation” strategies which aims at increasing the proportion of Beech, that is expected to better cope with climate change than the existing Norway spruce, and three conventional strategies including a “Do-nothing” alternative classified as “mitigation”, trying to keep rather higher levels of growing stock of spruce, were simulated using the empirical growth simulator BWINPro-S. A linear programming approach was adapted to simultaneously maximize the net present values of carbon sequestration and timber production subject to the two constraints of wood even flow and partial protection of the oldest (nature protection). The optimized plan, with the global utility of 11,687 €/ha in forty years, allocated a combination of silvicultural scenarios to the entire forest area. Overall, strategies classified as “mitigation” were favored, while strategies falling into the “adaptation”-category were limited to the youngest age-classes in the optimal solution. Carbon sequestration of the “Do-nothing” alternative was between 1.72 and 1.85 million tons higher than the other alternatives for the entire forest area while the differences between the adaptation and mitigation approaches were approximately 133,000 tons. Sensitivity analysis showed that a carbon price of 21 €/ t is the threshold at which carbon sequestration is promoted, while an interest rate of above 2

Fifty years of partial harvesting in a mixed mesophytic forest: composition and productivity

Treesearch

Thomas M. Schuler

2004-01-01

Long-term silvicultural trials contribute to sustainable forest management by providing a better scientific understanding of how forest ecosystems respond to periodic timber harvesting. In this study, species composition, diversity, and net periodic growth of tree species in a mixed mesophytic forest in the central Appalachians were evaluated after about a half century...

Revisiting the southern pine growth decline: Where are we 10 years later?

Treesearch

Gary L. Gadbury; Michael S. Williams; Hans T. Schreuder

2004-01-01

This paper evaluates changes in growth of pine stands in the state of Georgia, U.S.A., using USDA Forest Service Forest Inventory and Analysis (FIA) data. In particular, data representing an additional 10-year growth cy-cle has been added to previously published results from two earlier growth cycles. A robust regression procedure is combined with a bootstrap technique...

Nitrogen limitation of growth and nutrient dynamics in a disturbed mangrove forest, Indian River Lagoon, Florida

USGS Publications Warehouse

Feller, Ilka C.; Whigham, D.F.; McKee, K.L.; Lovelock, C.E.

2003-01-01

The objectives of this study were to determine effects of nutrient enrichment on plant growth, nutrient dynamics, and photosynthesis in a disturbed mangrove forest in an abandoned mosquito impoundment in Florida. Impounding altered the hydrology and soil chemistry of the site. In 1997, we established a factorial experiment along a tree-height gradient with three zones, i.e., fringe, transition, dwarf, and three fertilizer treatment levels, i.e., nitrogen (N), phosphorus (P), control, in Mosquito Impoundment 23 on the eastern side of Indian River. Transects traversed the forest perpendicular to the shoreline, from a Rhizophora mangle-dominated fringe through an Avicennia germinans stand of intermediate height, and into a scrub or dwarf stand of A. germinans in the hinterland. Growth rates increased significantly in response to N fertilization. Our growth data indicated that this site is N-limited along the tree-height gradient. After 2 years of N addition, dwarf trees resembled vigorously growing saplings. Addition of N also affected internal dynamics of N and P and caused increases in rates of photosynthesis. These findings contrast with results for a R. mangle-dominated forest in Belize where the fringe is N-limited, but the dwarf zone is P-limited and the transition zone is co-limited by N and P. This study demonstrated that patterns of nutrient limitation in mangrove ecosystems are complex, that not all processes respond similarly to the same nutrient, and that similar habitats are not limited by the same nutrient when different mangrove forests are compared.

Domination of hillslope denudation by tree uprooting in an old-growth forest

NASA Astrophysics Data System (ADS)

Phillips, Jonathan D.; Šamonil, Pavel; Pawlik, Łukasz; Trochta, Jan; Daněk, Pavel

2017-01-01

Razula forest preserve in the Carpathian Mountains of the Czech Republic is an unmanaged forest that has not been logged or otherwise anthropically disturbed for at least 83 years, preceded by only infrequent selective logging. We examined this 25 ha area to determine the dominant geomorphological processes on the hillslope. Tree uprooting displaces about 2.9 m3 of soil and regolith per year, representing about 1.5 uprooted trees ha- 1 yr- 1, based on forest inventory records dating back to 1972, and contemporary measurements of displaced soil and pit-mound topography resulting from uprooting. Pits and mounds occupy > 14% of the ground surface. Despite typical slope gradients of 0.05 mm- 1, and up to 0.41, little evidence of mass wasting (e.g., slump or flow scars or deposits, colluvial deposits) was noted in the field, except in association with pit-mound pairs. Small avalanche and ravel features are common on the upslope side of uproot pits. Surface runoff features were rare and poorly connected, but do include stemwash erosion associated with stemflow. No rills or channels were found above the valley bottom area, and only small, localized areas of erosion and forest litter debris indicating overland flow. Where these features occurred, they either disappeared a short distance downslope (indicating infiltration), or indicate flow into tree throw pits. Surface erosion is also inhibited by surface armoring of coarse rock fragments associated with uprooting, as well as by the nearly complete vegetation and litter cover. These results show that the combination of direct and indirect impacts of tree uprooting can dominate slope processes in old-growth, unmanaged forests. The greater observed expression of different hillslope processes in adjacent managed forests (where tree uprooting dynamics are blocked by management activities) suggests that human interventions can change the slope process regime in forest ecosystems.

International Trade In Forest Products

Treesearch

Jeffrey P. Prestemon; Joseph Buongiomo; David N. Wear; Jacek P. Siry

2003-01-01

The 21st century continues a trend of rapid growth in both international trade of forest products and a concern for forests. These two trends are connected. Forces causing trade growth are linked to the loss of native forest resources in some countries and the accumulation of nonnative forest resources in other countries. Factors increasing trade...

Missouri's forest resources in 2004

Treesearch

W. Keith Moser; Mark H. Hansen; Thomas Treiman; Bruce Moltzan; Robert Lawrence; Gary J. Brand

2006-01-01

Reports the initial results of five annual panels (2000-2004) of the inventory of Missouri's forest resources and one panel (2004) of growth, removals, and mortality. Includes information on forest area, number of trees, volume, biomass, growth, removals, mortality, and forest health.

Indiana's forest resources in 2004

Treesearch

Christopher Woodall; Gary Brand; Joey Gallion

2006-01-01

Reports the initial results of five annual panels (2000-2004) of the inventory of Indiana's forest resources and one panel (2004) of growth, removals, and mortality. Includes information on forest area, number of trees, volume, biomass, growth, removals, mortality, and forest health.

Ground-based forest harvesting effects on soil physical properties and Douglas-fir growth.

Treesearch

Adrian Ares; Thomas A. Terry; Richard E. Miller; Harry W. Anderson; Barry L. Flaming

2005-01-01

Soil properties and forest productivity can be affected by heavy equipment used for harvest and site preparation but these impacts vary greatly with site conditions and operational practices. We assessed the effects of ground-based logging on soil physical properties and subsequent Douglas-fir [Pseudotsuga menziesii (Mirb) Franco] growth on a highly...

Spatially nonrandom tree mortality and ingrowth maintain equilibrium pattern in an old-growth Pseudotsuga-Tsuga forest.

PubMed

Lutz, James A; Larson, Andrew J; Furniss, Tucker J; Donato, Daniel C; Freund, James A; Swanson, Mark E; Bible, Kenneth J; Chen, Jiquan; Franklin, Jerry F

2014-08-01

Mortality processes in old-growth forests are generally assumed to be driven by gap-scale disturbance, with only a limited role ascribed to density-dependent mortality, but these assumptions are rarely tested with data sets incorporating repeated measurements. Using a 12-ha spatially explicit plot censused 13 years apart in an approximately 500-year-old Pseudotsuga-Tsuga forest, we demonstrate significant density-dependent mortality and spatially aggregated tree recruitment. However, the combined effect of these strongly nonrandom demographic processes was to maintain tree patterns in a state of dynamic equilibrium. Density-dependent mortality was most pronounced for the dominant late-successional species, Tsuga heterophylla. The long-lived, early-seral Pseudotsuga menziesii experienced an annual stem mortality rate of 0.84% and no new recruitment. Late-seral species Tsuga and Abies amabilis had nearly balanced demographic rates of ingrowth and mortality. The 2.34% mortality rate for Taxus brevifolia was higher than expected, notably less than ingrowth, and strongly affected by proximity to Tsuga. Large-diameter Tsuga structured both the regenerating conspecific and heterospecific cohorts with recruitment of Tsuga and Abies unlikely in neighborhoods crowded with large-diameter competitors (P < 0.001). Density-dependent competitive interactions strongly shape forest communities even five centuries after stand initiation, underscoring the dynamic nature of even equilibrial old-growth forests.

AVIRIS spectral trajectories for forested areas of the Gifford Pinchot National Forest

NASA Technical Reports Server (NTRS)

Sabol, Donald E., Jr.; Smith, Milton O.; Adams, John B.; Zukin, Janet H.; Tucker, Compton J.; Roberts, Dar A.; Gillespie, Alan R.

1995-01-01

A simple mixing model employing reference endmembers (green vegetation, non-photosynthetic vegetation, soil and shade), and using 180 AVIRIS bands, was used to establish an interpretive framework for a forested area in the Pacific Northwest. A regrowth trend, based on changes in the endmember proportions, was defined for conifers that extends from clearcuts to mature forest, and by implication to old growth. Deciduous species within replanted forest plots caused the fractions to be displaced from the main coniferous regrowth trend and to move toward the green vegetation fraction. The results indicate that the spectral information in AVIRIS can be inverted to estimate approximate stand age and relative proportion of deciduous species in the context of the area studied. Using AVIRIS we measured a 3 to 5 percent increase in woody material in old-growth forest, as distinct from other mature forest. This result is consistent with a predicted increase in NPV in old-growth forest, based on field observations. Previous application of the mixing analysis to a TM image of the same area separated old growth based solely on the shade fraction; however the approach required successful removal of shade introduced by topography. Our new results suggest that with the high spectral resolution and high signal-to-noise of AVIRIS images it may be possible to characterize and map old-growth forests in the Northwest using both the NPV fraction and shade.

Do remnant old-growth trees accelerate rates of succession in mature Douglas-fir forests?

Treesearch

William S. Keeton; Jerry F. Franklin

2005-01-01

Biological legacies left by natural disturbances provide ecological functions throughout forest stand development, but their influences on processes of ecological succession are not completely understood. We investigated the successional role of one type of biological legacy: remnant old-growth trees persisting in mature Pseudotsuga menziesii (...

Forest restoration at Redwood National Park: exploring prescribed fire alternatives to second-growth management: a case study

Treesearch

Eamon Engber; Jason Teraoka; Phil van Mantgem

2017-01-01

Almost half of Redwood National Park is comprised of second-growth forests characterized by high stand density, deficient redwood composition, and low understory biodiversity. Typical structure of young redwood stands impedes the recovery of old-growth conditions, such as dominance of redwood (Sequoia sempervirens (D. Don) Endl.), distinct...

Sequential effects of severe drought and defoliation on tree growth and survival in a diverse temperate mesic forest

NASA Astrophysics Data System (ADS)

Matthes, J. H.; Pederson, N.; David, O.; Martin-Benito, D.

2017-12-01

Understanding the effects of climate change and biotic disturbance within diverse temperate mesic forests is complicated by the need to scale between impacts within individuals and across species in the community. It is not clear how these impacts within individuals and across a community influences the stand- and regional-scale response. Furthermore, co-occurring or sequential disturbances can make it challenging to interpret forest responses from observational data. In the northeastern United States, the 1960s drought was perhaps the most severe period of climatic stress within the past 300 years and negatively impacted the growth of individual trees across all species, but unevenly. Additionally, in 1981 the northeast experienced an outbreak of the defoliator Lymantria dispar, which preferentially consumes oak leaves, but in 1981 impacted a high proportion of other species as well. To investigate the effects of drought (across functional groups) and defoliation (within a functional group), we combined a long-term tree-ring dataset from an old-growth forest within the Palmaghatt Ravine in New York with a version of the Ecosystem Demography model that includes a scheme for representing forest insects and pathogens. We explored the sequential impacts of severe drought and defoliation on tree growth, community composition, and ecosystem-atmosphere interactions (carbon, water, and heat flux). W­e also conducted a set of modeling experiments with climate and defoliation disturbance scenarios to bound the potential long-term response of this forest to co-occurring and sequential drought-defoliator disturbances over the next fifty years.

Indiana's forest resources in 2005

Treesearch

Christopher Woodall; Gary Brand; Joey Gallion

2006-01-01

Reports the initial results of five annual panels (2001-2005) of the inventory of Indiana's forest resources and two panels (2004 and 2005) of growth, removals, and mortality. Includes information on forest area, number of trees, volume, biomass, growth, removals, mortality, and forest health.

Carbon dioxide exchange between an undisturbed old-growth temperate forest and the atmosphere

Treesearch

D.Y. Hollinger; F.M. Kelliher; J.N. Byers; J.E. Hunt; T.M. McSeveny; P.L. Weir

1994-01-01

We used the eddy-correlation technique to investigate the exchange of C02 between an undisturbed old-growth forest and the atmosphere at a remote Southern Hemisphere site on 15 d between 1989 and 1990. Our goal was to determine how environmental factors regulate ecosystem CO2 exchange, and to test whether present knowledge...

Stand Dynamics in an Old-Growth Hardwood Forest in Southern Illinois, USA

Treesearch

James J. Zaczek; John W. Groninger; J. W. Van Sambeek

2002-01-01

Kaskaskia Woods, a 7.4-ha old-growth hardwood forest in southern Illinois, USA, has been managed as a natural area and protected from disturbance since 1933. In 1935, eight 0.1-ha plots were installed and all trees 4 cm dbh or larger were tagged and inventoried. Trees were remeasured for survival, ingrowth (new trees >4 cm), and diameter (dbh) in 1940, 1958, 1965,...

Wood phenology, not carbon input, controls the interannual variability of wood growth in a temperate oak forest.

PubMed

Delpierre, Nicolas; Berveiller, Daniel; Granda, Elena; Dufrêne, Eric

2016-04-01

Although the analysis of flux data has increased our understanding of the interannual variability of carbon inputs into forest ecosystems, we still know little about the determinants of wood growth. Here, we aimed to identify which drivers control the interannual variability of wood growth in a mesic temperate deciduous forest. We analysed a 9-yr time series of carbon fluxes and aboveground wood growth (AWG), reconstructed at a weekly time-scale through the combination of dendrometer and wood density data. Carbon inputs and AWG anomalies appeared to be uncorrelated from the seasonal to interannual scales. More than 90% of the interannual variability of AWG was explained by a combination of the growth intensity during a first 'critical period' of the wood growing season, occurring close to the seasonal maximum, and the timing of the first summer growth halt. Both atmospheric and soil water stress exerted a strong control on the interannual variability of AWG at the study site, despite its mesic conditions, whilst not affecting carbon inputs. Carbon sink activity, not carbon inputs, determined the interannual variations in wood growth at the study site. Our results provide a functional understanding of the dependence of radial growth on precipitation observed in dendrological studies. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Evaluation of Forest Health Conditions using Unmanned Aircraft Systems (UAS)

NASA Astrophysics Data System (ADS)

Hatfield, M. C.; Heutte, T. M.

2016-12-01

US Forest Service Alaska Region Forest Health Protection (FHP) and University of Alaska Fairbanks, Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) are evaluating capability of Unmanned Aerial Systems (UAS) to monitor forest health conditions in Alaska's Interior Region. In July 2016, the team deployed UAS at locations in the Tanana Valley near Fairbanks in order to familiarize FHP staff with capabilities of UAS for evaluating insect and disease damage. While many potential uses of UAS to evaluate and monitor forest health can be envisioned, this project focused on use of a small UAS for rapid assessment of insect and disease damage. Traditional ground-based methods are limited by distance from ground to canopy and inaccessibility of forest stands due to terrain conditions. Observation from fixed-wing aircraft provide a broad overview of conditions but are limited by minimum safe flying altitude (500' AGL) and aircraft speed ( 100 mph). UAS may provide a crucial bridge to fill in gaps between ground and airborne methods, and offer significant cost savings and greater flexibility over helicopter-based observations. Previous uses of UAS for forest health monitoring are limited - this project focuses on optimizing choice of vehicle, sensors, resolution and area scanned from different altitudes, and use of visual spectrum vs NIR image collection. The vehicle selected was the ACUASI Ptarmigan, a small hexacopter (based on DJI S800 airframe and 3DR autopilot) capable of carrying a 1.5 kg payload for 15 min for close-range environmental monitoring missions. Sites were chosen for conditions favorable to UAS operation and presence of forest insect and disease agents including spruce broom rust, aspen leaf miner, birch leaf roller, and willow leafblotch miner. A total of 29 flights were conducted with 9000+ images collected. Mission variables included camera height, UAS speed, and medium- (Sony NEX-7) vs low-resolution (GoPro Hero) cameras. Invaluable

Evaluation of hydrologic equilibrium in a mountainous watershed: incorporating forest canopy spatial adjustment to soil biogeochemical processes

NASA Astrophysics Data System (ADS)

Mackay, D. Scott

Hydrologic equilibrium theory has been used to describe both short-term regulation of gas exchange and long-term adjustment of forest canopy density. However, by focusing on water and atmospheric conditions alone a hydrologic equilibrium may impose an oversimplification of the growth of forests adjusted to hydrology. In this study nitrogen is incorporated as a third regulation of catchment level forest dynamics and gas exchange. This was examined with an integrated distributed hydrology and forest growth model in a central Sierra Nevada watershed covered primarily by old-growth coniferous forest. Water and atmospheric conditions reasonably reproduced daily latent heat flux, and predicted the expected catenary trend of leaf area index (LAI). However, it was not until the model was provided a spatially detailed description of initial soil carbon and nitrogen pools that spatial patterns of LAI were generated. This latter problem was attributed to a lack of soil history or memory in the initialization of the simulations. Finally, by reducing stomatal sensitivity to vapor pressure deficit (VPD) the canopy density increased when water and nitrogen limitations were not present. The results support a three-control hydrologic equilibrium in the Sierra Nevada watershed. This has implications for modeling catchment level soil-vegetation-atmospheric interactions over interannual, decade, and century time-scales.

Interannual climatic variation mediates elevated CO2 and O3 effects on forest growth

Treesearch

Mark E. Kubiske; Vanessa A. Quinn; Warren E. Heilman; Evan P. McDonald; Paula E. Marquardt; Ron M. Teclaw; Alexander L. Friend; David F. Karnosky

2006-01-01

We analyzed growth data from model aspen (Populus tremuloides Michx.) forest ecosystems grown in elevated atmospheric carbon dioxide ([CO2]; 518?LL-1) and ozone concentrations ([O3]; 1.5 x background of 30-40 nL L-1 during daylight hours) for 7 years using...

[Dynamics of Amomum villosum growth and its fruit yield cultivated under tropical forests].

PubMed

Zheng, Zheng; Gan, Jianmin; Feng, Zhili; Meng, Ying

2004-01-01

Investigations on the dynamics of Amomum villosum growth and its fruit yield cultivated under tropical ravine rainforest and secondary forest at different elevations in Xishuangbanna showed that the yield of A. villosum was influenced by the site age, sun light level of understorey, and water stress in dry season. The fruit yield and mature plant density decreased with increasing age of the A. villosum site. The fruit yield increased with sun light level when the light level in understorey was under 35% of full sun light (P < 0.05). The fruit yield at the lower site by stream was significantly higher than that at upper site (P < 0.05). The yield difference between ravine rainforest and secondary forest was not significant. Planned cultivation of A. villosum in the secondary forest of the shifting cultivation land by ravine from 800-1000 m elevation instead of customary cultivation in the ravine rainforest, could not only resolve the problem of the effect of light deficiency in understorey and water stress in the dry season on A. villosum fruit yield, but also be useful to protect the tropical ravine rain forest.

Effects of high- and low-intensity fires on soil properties and plant growth in a Bolivian dry forest

Treesearch

Deborah K. Kennard; H.L. Gholz

2001-01-01

We compared soil nutrient availabiiity and soil physical properties among four treatments (high-intensity fire, low- intensity fire, plant removal, and harvesting gap) and a control (intact forest understory) over a period of 18 months in a tropical dry forest in Bolivia. The effect of treatments on plant growth was tested using a shade intolerant tree species (

EFFECTS OF CARBON DIOXIDE AND OZONE ON GROWTH AND BIOMASS ALLOCATION IN PINUS PONDEROSA

EPA Science Inventory

The future productivity of forests will be affected by combinations of elevated atmospheric CO2 and O3. Because productivity of forests will, in part, be determined by growth of young trees, we evaluated shoot growth and biomass responses of Pinus ponderosa seedlings exposed to ...

Edge effects on growth and biomass partitioning of an Amazonian understory herb (Heliconia acuminata; Heliconiaceae).

PubMed

Bruna, Emilio M; de Andrade, Ana Segalin

2011-10-01

After deforestation, environmental changes in the remaining forest fragments are often most intense near the forest edge, but few studies have evaluated plant growth or plasticity of plant growth in response to edge effects. In a 2-year common garden experiment, we compared biomass allocation and growth of Heliconia acuminata with identical genotypes grown in 50 × 35 m common gardens on a 25-year-old edge and in a forest interior site. Genetically identical plants transplanted to the forest edge and understory exhibited different patterns of growth and biomass allocation. However, individuals with identical genotypes in the same garden often had very different responses. Plants on forest edges also had higher growth rates and increased biomass at the end of the experiment, almost certainly due to the increased light on the forest edge. With over 70000 km of forest edge created annually in the Brazilian Amazon, phenotypic plasticity may play an important role in mediating plant responses to these novel environmental conditions.

Huckleberry abundance, stand conditions, and use in western Oregon: evaluating the role of forest management.

Treesearch

Becky K Kerns; Susan J. Alexander; John D. Bailey

2004-01-01

Huckleberries are major components of the understory vegetation in coniferous Pacific Northwest forests of the United States. Vaccinium species also have a long history of human use. However, little research has been done to ascertain how they respond to common forest management practices. We used data obtained from old-growth, young thinned, and...

Drought stress, growth and nonstructural carbohydrate dynamics of pine trees in a semi-arid forest.

PubMed

Klein, Tamir; Hoch, Günter; Yakir, Dan; Körner, Christian

2014-09-01

In trees exposed to prolonged drought, both carbon uptake (C source) and growth (C sink) typically decrease. This correlation raises two important questions: (i) to what degree is tree growth limited by C availability; and (ii) is growth limited by concurrent C storage (e.g., as nonstructural carbohydrates, NSC)? To test the relationships between drought, growth and C reserves, we monitored the changes in NSC levels and constructed stem growth chronologies of mature Pinus halepensis Miller trees of three drought stress levels growing in Yatir forest, Israel, at the dry distribution limit of forests. Moderately stressed and stressed trees showed 34 and 14% of the stem growth, 71 and 31% of the sap flux density, and 79 and 66% of the final needle length of healthy trees in 2012. In spite of these large reductions in growth and sap flow, both starch and soluble sugar concentrations in the branches of these trees were similar in all trees throughout the dry season (2-4% dry mass). At the same time, the root starch concentrations of moderately stressed and stressed trees were 47 and 58% of those of healthy trees, but never <2% dry mass. Our results show that all the studied trees maintain a fairly good coordination between C supply and demand, and even during prolonged drought there is more than one way for a tree to maintain a positive C balance. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Long-term growth-increment chronologies reveal diverse influences of climate forcing on freshwater and forest biota in the Pacific Northwest

USGS Publications Warehouse

Black, Bryan A.; Dunham, Jason B.; Blundon, Brett W.; Brim-Box, Jayne; Tepley, Alan J.

2015-01-01

Analyses of how organisms are likely to respond to a changing climate have focused largely on the direct effects of warming temperatures, though changes in other variables may also be important, particularly the amount and timing of precipitation. Here, we develop a network of eight growth-increment width chronologies for freshwater mussel species in the Pacific Northwest, United States and integrate them with tree-ring data to evaluate how terrestrial and aquatic indicators respond to hydroclimatic variability, including river discharge and precipitation. Annual discharge averaged across water years (October 1–September 30) was highly synchronous among river systems and imparted a coherent pattern among mussel chronologies. The leading principal component of the five longest mussel chronologies (1982–2003; PC1mussel) accounted for 47% of the dataset variability and negatively correlated with the leading principal component of river discharge (PC1discharge; r = −0.88; P < 0.0001). PC1mussel and PC1discharge were closely linked to regional wintertime precipitation patterns across the Pacific Northwest, the season in which the vast majority of annual precipitation arrives. Mussel growth was also indirectly related to tree radial growth, though the nature of the relationships varied across the landscape. Negative correlations occurred in forests where tree growth tends to be limited by drought while positive correlations occurred in forests where tree growth tends to be limited by deep or lingering snowpack. Overall, this diverse assemblage of chronologies illustrates the importance of winter precipitation to terrestrial and freshwater ecosystems and suggests that a complexity of climate responses must be considered when estimating the biological impacts of climate variability and change.

Long-term growth-increment chronologies reveal diverse influences of climate forcing on freshwater and forest biota in the Pacific Northwest.

PubMed

Black, Bryan A; Dunham, Jason B; Blundon, Brett W; Brim-Box, Jayne; Tepley, Alan J

2015-02-01

Analyses of how organisms are likely to respond to a changing climate have focused largely on the direct effects of warming temperatures, though changes in other variables may also be important, particularly the amount and timing of precipitation. Here, we develop a network of eight growth-increment width chronologies for freshwater mussel species in the Pacific Northwest, United States and integrate them with tree-ring data to evaluate how terrestrial and aquatic indicators respond to hydroclimatic variability, including river discharge and precipitation. Annual discharge averaged across water years (October 1-September 30) was highly synchronous among river systems and imparted a coherent pattern among mussel chronologies. The leading principal component of the five longest mussel chronologies (1982-2003; PC1(mussel)) accounted for 47% of the dataset variability and negatively correlated with the leading principal component of river discharge (PC1(discharge); r = -0.88; P < 0.0001). PC1(mussel) and PC1(discharge) were closely linked to regional wintertime precipitation patterns across the Pacific Northwest, the season in which the vast majority of annual precipitation arrives. Mussel growth was also indirectly related to tree radial growth, though the nature of the relationships varied across the landscape. Negative correlations occurred in forests where tree growth tends to be limited by drought while positive correlations occurred in forests where tree growth tends to be limited by deep or lingering snowpack. Overall, this diverse assemblage of chronologies illustrates the importance of winter precipitation to terrestrial and freshwater ecosystems and suggests that a complexity of climate responses must be considered when estimating the biological impacts of climate variability and change. © 2014 John Wiley & Sons Ltd.

Patterns of tree growth in relation to environmental variability in the tropical dry deciduous forest at Mudumalai, southern India.

PubMed

Nath, Cheryl D; Dattaraja, H S; Suresh, H S; Joshi, N V; Sukumar, R

2006-12-01

Tree diameter growth is sensitive to environmental fluctuations and tropical dry forests experience high seasonal and inter-annual environmental variation. Tree growth rates in a large permanent plot at Mudumalai, southern India, were examined for the influences of rainfall and three intrinsic factors (size, species and growth form) during three 4-year intervals over the period 1988-2000. Most trees had lowest growth during the second interval when rainfall was lowest, and skewness and kurtosis of growth distributions were reduced during this interval. Tree diameter generally explained less than 10% of growth variation and had less influence on growth than species identity or time interval. Intraspecific variation was high, yet species identity accounted for up to 16% of growth variation in the community. There were no consistent differences between canopy and understory tree growth rates; however, a few subgroups of species may potentially represent canopy and understory growth guilds. Environmentally-induced temporal variations in growth generally did not reduce the odds of subsequent survival. Growth rates appear to be strongly influenced by species identity and environmental variability in the Mudumalai dry forest. Understanding and predicting vegetation dynamics in the dry tropics thus also requires information on temporal variability in local climate.

Reconstructed old-growth forest stand structure and composition of two stands on the Olympic Peninsula, Washington state

Treesearch

David H. Peter; Constance A. Harrington

2010-01-01

We reconstructed the stand structure and composition for two western Washington old-growth forest stands harvested around 1930 (named Fresca and Rail) from field and historical data. Both old-growth stands had a codominant or dominant 250-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) overstory with a few scattered older Douglas-fir....

Oklahoma's forests, 2014

Treesearch

Kerry Dooley; KaDonna Randolph

2017-01-01

This resource bulletin describes the principal findings of the 2014 forest inventory of Oklahoma (conducted 2009–2014) and examines changes since the previous survey of Oklahoma in 2008. Topics presented include forest area, volume, biomass, number of trees, growth, mortality, removals, forest health, silvicultural treatments, and forest ownership.

Developing Inventory Projection Models Using Empirical Net Forest Growth and Growing-Stock Density Relationships Across U.S. Regions and Species Group

Treesearch

Prakash Nepal; Peter J. Ince; Kenneth E. Skog; Sun J. Chang

2012-01-01

This paper describes a set of empirical net forest growth models based on forest growing-stock density relationships for three U.S. regions (North, South, and West) and two species groups (softwoods and hardwoods) at the regional aggregate level. The growth models accurately predict historical U.S. timber inventory trends when we incorporate historical timber harvests...

An analysis of Ohio's forest resources